build: Add common CLEANFILES and DISTCLEANFILES to common-rules.mk.

By adding common CLEANFILES and DISTCLEANFILES variables to
common-rules.mk, we can remove these from most other Makefiles, and
also clean files more consistently.

Note that bin_PROGRAMS are already cleaned by 'make clean', so I
removed cases where these were unnecessarily added to CLEANFILES.

lua/Makefile.am

@@ -27,9 +27,7 @@ EXTRA_DIST = \
 	$(generator_built) \
 	run-bindtests
 
-CLEANFILES = \
-	*~ \
-	bindtests.tmp \
+CLEANFILES += \
 	guestfs.so
 
 if HAVE_LUA

lua/examples/Makefile.am

@@ -23,10 +23,6 @@ EXTRA_DIST = \
 	inspect_vm.lua \
 	guestfs-lua.pod
 
-CLEANFILES = \
-	guestfs-lua.3 \
-	stamp-guestfs-lua.pod
-
 man_MANS = guestfs-lua.3
 noinst_DATA = $(top_builddir)/website/guestfs-lua.3.html