shell: Don't ask too much from windows

Handling redirections is a bit too complicated for windows, so let's not
push the old fellow too much and just disable output redirection.

https://bugzilla.gnome.org/show_bug.cgi?id=729190
cerbero: Allow applying patches on sources from git repo

It might fail because of new commits on the repo but if the user
specifies patches to be applied he expects that to happen!
commands: Properly print variants when show-config
recipes: Rename gst-python to gst-python-1.0 so it is synced with other modules
bootstrap: Download wglext.h when cross-compiling for windows
recipes: gtk-doc: Use non-broken tarball location

current gtk-doc 1.20 tarball isn't usable on windows

Use a re-tarballed variant in the time being

More info at:
https://bugzilla.gnome.org/show_bug.cgi?id=722621
bootstrap: Use cmake binaries on windows/osx

And update the README for the various requirements. Some URI have
changed since the last time it was updated.
recipes: Update gmp tarball location

for some reason the gmp server causes issues with windows wget
Improve handling of invalid recipes
Add missing arguments constructing the InvaliRecipeError
libvpx: Update to 1.3.0

VP9 support \o/

Also contains a fixed pkg-config file that makes encoder
detection in gst-plugins-good's configure work again.

https://bugzilla.gnome.org/show_bug.cgi?id=729755
build-tools: build glib-tools in Lucid and Natty
wix: add the package directory in the properties list
osx: add CFBundleExecutable, needed by spotlight
Handle failures when failed to get cache/file directories on Android more gracefully

And clean up some local references in error cases.
libvpx: fix build with ccache enabled
recipes: gettext: bump to 0.18.3.2
recipes: libvorbis: Bump to 1.3.4
recipes: freetype: Bump to 2.5.3
recipes: fontconfig: Bump to 2.11.1