Move virt tools (virt-cat, virt-edit etc) into tools/ subdirectory.

This moves the tool programs into a single directory:
  cat/* -> tools/virt-cat
  df/* -> tools/virt-df
  edit/* -> tools/virt-edit
  rescue/* -> tools/virt-rescue

This in itself simplifies the build process because we only need
one Makefile and one copy of 'run-locally'.

'run-*-locally' has become just 'run-locally' and takes an extra
parameter which is the name of the tool, eg:
  run-locally cat [virt-cat params...]

virt-inspector stays in its own directory, because this contains
more than just a single Perl script.

HACKING

@@ -68,9 +68,6 @@ Directories
 appliance/
         The qemu appliance, build scripts and so on.
 
-cat/
-        The virt-cat tool.
-
 capitests/
         Automated tests of the C API.
 
@@ -80,12 +77,6 @@ contrib/
 daemon/
         The daemon that runs inside the guest and carries out actions.
 
-df/
-        The virt-df tool.
-
-edit/
-        The virt-edit tool.
-
 examples/
         The examples.
 
@@ -125,12 +116,15 @@ python/
 regressions/
         Regression tests.
 
-rescue/
-        The virt-rescue tool.
-
 ruby/
         Ruby bindings.
 
+tools/
+	Command line tools like virt-cat, virt-df, virt-edit and more.
+	In versions <= 1.0.73 these were all in separate directories
+	like cat/, df/, edit/, but since then we moved them all into
+	one directory to simplify builds.
+
 src/
         Source code to the C library.
         Also contains the crucial generator program.