inspection: Use guestfs_is_{dir,file} in preference to guestfs_exists.

Where possible, using this is more accurate, and it helps when
trying to do fuzz testing.
perl: Add rules + environment variables so Perl code can be valgrinded.
inspection: Add a fuzz-test of inspection.
docs: Updated release versions which fix CVE-2013-2124.
Version 1.23.2.
Revert "perl: Fix build and test to work with separated builds."

This reverts commit 4ea016dae96ed4fc3ca6d057f17fde9697f0e627.
perl: Use symlink hack from hivex
python: Build extension with PEP-3149 compliant suffix if defined.
ocamldoc: Depend directly on guestfs.mli, guestfs.ml files, not wildcards.
generator: Don't always recurse into the generator directory.

Previously, every subdirectory that contained generated files would
cause a recursion into the ../generator directory.  This was slow and
unnecessary.  Only recurse if the generator actually needs to be
rerun.

Note this changes the semantics slightly: For example if you added a
new action and just ran `make -C ocaml' then previously the generator
would be rerun, but now it would not.  However I'm not convinced the
previous semantics were that useful, particularly considering that
with this change a simple `make' is much faster.
build: Simplify and speed up expression that generates po/POTFILES.

This has to run on every build, so:

- Use two grep commands instead of lots.

- Remove unnecessary use of sed.

- Remove some obsolete directories that haven't existed for a long time.
Quote ./configure --help output (options) properly.
build: Don't include subdir-rules.mk in top level Makefile.am.

Also there are no generated files at the top level, so no need to
mention $(generator_built) in this file.
build: Add common-rules.mk, common rules for all Makefiles.

This file is mainly a central place to:

 - include localenv if it exists, and

 - define the RHEL 5 backwards compatibility macros, instead of
   spreading them over every other file.
ocaml: Build dependencies for tests too.
Set DISTRO to SUSE if /etc/SuSE-release exists

Signed-off-by: Olaf Hering <olaf@aepfle.de>
inspection: Refactor windows systemroot detection to allow re-use

This change refactors guestfs___has_windows_systemroot to
guestfs___get_windows_systemroot. The new function returns a
dynamically allocated char * which must be freed.

The new function is no less efficient than before, as it returns the
result of guestfs___case_sensitive_path_silently, which is required
anyway. The new code is slightly more efficient than before, as it
re-uses the result of this testing in guestfs___check_windows_root
rather than running it again.
inspect: Add internal match6 function
inspect: Partial support for non-standard windows system root

Support arbitrary windows system root for pre-vista systems where
boot.ini is on the same partition as the system root.
inspection: Reformat is_systemroot declaration.

Just code motion.