add gettext support, and a French translation; patch by Claude Paroz, with

* Makefile.plain, jhbuild/utils/packagedb.py, jhbuild/utils/unpack.py,
jhbuild/utils/httpcache.py, jhbuild/utils/cmds.py,
jhbuild/commands/autobuild.py, jhbuild/commands/base.py,
jhbuild/commands/info.py, jhbuild/commands/bootstrap.py,
jhbuild/commands/tinderbox.py, jhbuild/commands/__init__.py,
jhbuild/commands/checkbranches.py, jhbuild/commands/gui.py,
jhbuild/commands/rdepends.py, jhbuild/commands/sanitycheck.py,
jhbuild/frontends/autobuild.py, jhbuild/frontends/terminal.py,
jhbuild/frontends/gtkui.py, jhbuild/frontends/buildscript.py,
jhbuild/modtypes/autotools.py, jhbuild/modtypes/mozillamodule.py,
jhbuild/modtypes/waf.py, jhbuild/modtypes/__init__.py,
jhbuild/modtypes/linux.py, jhbuild/modtypes/cmake.py,
jhbuild/modtypes/perl.py, jhbuild/modtypes/distutils.py,
jhbuild/modtypes/mesa.py, jhbuild/versioncontrol/cvs.py,
jhbuild/versioncontrol/darcs.py, jhbuild/versioncontrol/arch.py,
jhbuild/versioncontrol/bzr.py, jhbuild/versioncontrol/hg.py,
jhbuild/versioncontrol/mtn.py, jhbuild/versioncontrol/__init__.py,
jhbuild/versioncontrol/tarball.py, jhbuild/versioncontrol/git.py,
jhbuild/versioncontrol/svn.py, jhbuild/moduleset.py,
jhbuild/monkeypatch.py, jhbuild/main.py, jhbuild/config.py,
tests/tests.py, onfigure.ac, Makefile.am, po/LINGUAS, po/fr.po,
po/Makevars, po/POTFILES.in: add gettext support, and a French
translation; patch by Claude Paroz, with a few fixes by myself
(closes: #531417)


svn path=/trunk/; revision=2079