Minor cosmetic cleanup: fix C style comments

Replace C++ and Java style comments by C style comments.
Improve OSX build instructions

Add note about XCode,
add file descriptions,
fix broken links,
fix curl parameters,
add structure,
improve wording,
improve layout.
OSX bundler: fix link to .plist file

Refer to info-2.8-python.plist instead of info-2.8.8-python.plist.
OSX bundler: make launcher more generic

Rename the launcher to launcher-python.sh to make it also usable for
GIMP-master.
OSX JHBuild: fix some issues

Fix broken links,
use stable glib version,
GEGL: check out from repository instead of using tarball,
fix libgexiv2 issue,
use su-v's patch for OS X builds,
use newer iso-codes version.
OS X build: fix wrong XCode-Path

Fixes a problem that occured on OS X 10.9: JHBuild was not able to find
the existing $HOME/.jhbuildrc-gimp anymore. It turned out that
_xcodepath (now) needs to be platform independent.
Thanks to Daniel Sabo!
Add OS X build configuration for GIMP master

Add configuration for gtk-mac-bundler,
add OS X application metadata file.
OSX build: use autogen-template for different configure syntax

Gexiv2 and OpenSSL require an extra syntax to set prefix and libdir.
Use JHBuilds autogen-template parameter to set them properly.
OS X build: update OpenSSL dependency

Update the OpenSSL dependency to version 1.0.1g,
which fixes the SSL Heartbleed bug.
OS X build: fix poppler issues

The dependency 'Poppler' fails to build on OS X 10.9 with Clang
(Apple LLVM version 5.1 (clang-503.0.40) (based on LLVM 3.4svn))
because it contains the GCC compiler flag '-fno-check-new',
which is unsupported in Clang. Thus silencing all warnings from
this dependency.
OSX build readme: fix typo
OS X build: format JHBuild module file

Improve formatting of gimp.modules for better maintainability.
OS X build: update and fix libgcrypt and libgpg-error dependencies

Update dependency versions. Fix build errors. Exclude libgcrypt's doc 
directory from build, because it introduces new dependencies and we 
don't need it.
OS X build: fix GVFS dependency

Update glib, glib-networking, shared-mime-info, libsoup to latest
versions. Re-enable building GIMP with GVFS. Fix formatting.
OS X build: replace 2.8.8 target by gimp-osx target

Remove the outdated gimp-2.8.8 target, add target 'gimp-osx' for testing
the changes together.
app: add some CPPFLAGS in core/Makefile.am to fix the build on OSX

cherry-picked and adapted to gimp-2-8 from
00cd9b4e47dea4b4f51da60cb03fa2d575dcdb88

Resolved conflicts:
	app/core/Makefile.am
configure: Also search for the -gtk2 version of mac integration

If a suffixed version is not found it will still fall back to
searching for the old version.

Cherry-picked and adapted to gimp-2-8 from
f6533db8b739b95ca5d71c2d5ac2b28c54c650bf

Resolved conflicts:
	configure.ac
OS X build: update build instructions in README

Update gtk-mac-bundler preparations. Add line to run gtk-mac-bundler in
a JHBuild shell. Add gtk-mac-bundler instructions for building
gimp-master.
Split OS X launcher into 2.8 and master versions

GIMP launcher for GIMP 2.8 and master differ in the GEGL path. Otherwise
GIMP master on OS X will not start due to unfound GEGL.
Add missing language files to OS X bundler

Fix typo (filename.mo). Add missing language files for GIMP and its
dependencies. Prepare translation of OS X application menu strings.