docs: hacking: Fix the headings.

Just grouping things more logically.

docs/guestfs-hacking.pod

@@ -6,7 +6,7 @@ guestfs-hacking - extending and contributing to libguestfs
 
 This manual page is for hackers who want to extend libguestfs itself.
 
-=head1 OVERVIEW OF THE SOURCE CODE
+=head1 THE SOURCE CODE
 
 Libguestfs source is located in the github repository
 L<https://github.com/libguestfs/libguestfs>
@@ -37,7 +37,7 @@ functions in files under F<daemon>.
 
 To build from source, first read the L<guestfs-building(1)>.
 
-=head1 SOURCE CODE SUBDIRECTORIES
+=head2 SOURCE CODE SUBDIRECTORIES
 
 There are a lot of subdirectories in the source tree!  Which ones
 should you concentrate on first?  F<lib> and F<daemon> which contain
@@ -316,7 +316,7 @@ Language bindings.
 
 =back
 
-=head1 THE BUILD SYSTEM
+=head2 THE BUILD SYSTEM
 
 Libguestfs uses the GNU autotools build system (autoconf, automake,
 libtool).
@@ -337,7 +337,9 @@ There are many make targets.  Use this command to list them all:
 
  make help
 
-=head1 ADDING A NEW API
+=head1 EXTENDING LIBGUESTFS
+
+=head2 ADDING A NEW API
 
 Because large amounts of boilerplate code in libguestfs are generated,
 this makes it easy to extend the libguestfs API.
@@ -392,7 +394,7 @@ Note that you don't need to implement the RPC, language bindings,
 manual pages or anything else.  It's all automatically generated from
 the OCaml description.
 
-=head2 Adding tests for an API
+=head3 Adding tests for an API
 
 You can supply zero or as many tests as you want per API call.  The
 tests can either be added as part of the API description
@@ -462,7 +464,7 @@ Packagers can run only certain tests by setting for example:
 See F<tests/c-api/tests.c> for more details of how these environment
 variables work.
 
-=head2 Debugging new APIs
+=head3 Debugging new APIs
 
 Test new actions work before submitting them.
 
@@ -472,7 +474,7 @@ Debugging the daemon is a problem because it runs inside a minimal
 environment.  However you can fprintf messages in the daemon to
 stderr, and they will show up if you use C<guestfish -v>.
 
-=head1 ADDING A NEW LANGUAGE BINDING
+=head2 ADDING A NEW LANGUAGE BINDING
 
 All language bindings must be generated by the generator
 (see the F<generator> subdirectory).
@@ -481,7 +483,7 @@ There is no documentation for this yet.  We suggest you look
 at an existing binding, eg. F<generator/ocaml.ml> or
 F<generator/perl.ml>.
 
-=head2 Adding tests for language bindings
+=head3 Adding tests for language bindings
 
 Language bindings should come with tests.  Previously testing of
 language bindings was rather ad-hoc, but we have been trying to
@@ -521,7 +523,7 @@ This is the numbering scheme used by the tests:
 To save time when running the tests, only 100, 430, 800+, 900+ should
 launch the handle.
 
-=head1 FORMATTING CODE
+=head2 FORMATTING CODE
 
 Our C source code generally adheres to some basic code-formatting
 conventions.  The existing code base is not totally consistent on this
@@ -554,7 +556,7 @@ If you use Emacs, add the following to one of one of your start-up files
                                (buffer-file-name))
                            (libguestfs-c-mode))))
 
-=head1 TESTING YOUR CHANGES
+=head2 TESTING YOUR CHANGES
 
 Turn warnings into errors when developing to make warnings hard to
 ignore:
@@ -775,7 +777,7 @@ have to modify the F<Makefile.am> like this:
 In either case, check that the right program is being tested by
 examining the F<tmp/valgrind*> log files carefully.
 
-=head1 SUBMITTING PATCHES
+=head2 SUBMITTING PATCHES
 
 Submit patches to the mailing list:
 L<http://www.redhat.com/mailman/listinfo/libguestfs>
@@ -784,7 +786,7 @@ and CC to L<rjones@redhat.com>.
 You do not need to subscribe to the mailing list if you don't want to.
 There may be a short delay while your message is moderated.
 
-=head1 DAEMON CUSTOM PRINTF FORMATTERS
+=head2 DAEMON CUSTOM PRINTF FORMATTERS
 
 In the daemon code we have created custom printf formatters C<%Q> and
 C<%R>, which are used to do shell quoting.
@@ -815,7 +817,7 @@ quoted because they are not passed via the shell (instead, straight to
 exec).  You probably want to use the C<sysroot_path()> function
 however.
 
-=head1 INTERNATIONALIZATION (I18N) SUPPORT
+=head2 INTERNATIONALIZATION (I18N) SUPPORT
 
 We support i18n (gettext anyhow) in the library.
 
@@ -828,7 +830,9 @@ into the appliance.
 Debugging messages are never translated, since they are intended for
 the programmers.
 
-=head1 HOW OCAML PROGRAMS ARE COMPILED AND LINKED
+=head1 MISCELLANEOUS TOPICS
+
+=head2 HOW OCAML PROGRAMS ARE COMPILED AND LINKED
 
 Mostly this section is "how we make automake & ocamlopt work together"
 since OCaml programs themselves are easy to compile.
@@ -886,7 +890,7 @@ it will not add them all automatically.
 
 =back
 
-=head1 VIRT-V2V
+=head2 VIRT-V2V
 
 First a little history.  Virt-v2v has been through at least two
 complete rewrites, so this is probably about the third version (but we
@@ -929,7 +933,7 @@ Every other file in this directory is a support module / library of
 some sort.  Some code is written in C, especially where we want to use
 an external C library such as libxml2.
 
-=head1 VIRT-P2V
+=head2 VIRT-P2V
 
 Virt-p2v is a front end on virt-v2v.  ie. All it does is act as a GUI
 front end, and it calls out to virt-v2v to perform the actual
@@ -938,7 +942,7 @@ is Gtk (GUI) code, or supporting code for talking to the remote
 conversion server.  There is no special support for physical machines
 in virt-v2v.  They are converted in the same way as foreign VMs.
 
-=head2 Running virt-p2v
+=head3 Running virt-p2v
 
 You can run the F<p2v/virt-p2v> binary directly, but it will try to
 convert your machine's real F</dev/sda> which is unlikely to work
@@ -969,7 +973,7 @@ below):
 
  make -C p2v run-virt-p2v-non-gui-conversion
 
-=head2 Understanding the virt-p2v code
+=head3 Understanding the virt-p2v code
 
 I<See also:> L<virt-p2v(1)/HOW VIRT-P2V WORKS>
 
@@ -1001,7 +1005,9 @@ if you patch miniexpect.c, then please make sure the changes get
 reflected in miniexpect's upstream too:
 F<http://git.annexia.org/?p=miniexpect.git;a=summary>)
 
-=head1 MAKING A STABLE RELEASE
+=head1 MAINTAINER TASKS
+
+=head2 MAKING A STABLE RELEASE
 
 When we make a stable release, there are several steps documented
 here.  See L<guestfs(3)/LIBGUESTFS VERSION NUMBERS> for general information