libglib2: bump to version 2.40.0

Signed-off-by: Hadrien Boutteville <hadrien.boutteville@gmail.com>
pango: bump to version 1.36.3

Note: HarfBuzz is needed to build Pango. Configure does not return an
error if HarfBuzz is missing, but without HarfBuzz it can't enable any
backends.

Signed-off-by: Hadrien Boutteville <hadrien.boutteville@gmail.com>
cairo: add freetype dependency for freetype support

Signed-off-by: Hadrien Boutteville <hadrien.boutteville@gmail.com>
libgtk3: new package - not tested

Signed-off-by: Hadrien Boutteville <hadrien.boutteville@gmail.com>
libgtk3: add missing entry in package/Config.in

Signed-off-by: Hadrien Boutteville <hadrien.boutteville@gmail.com>
libgtk3: fix syntax in Config.in

Signed-off-by: Hadrien Boutteville <hadrien.boutteville@gmail.com>
libgtk3: add patch to fix gtk-doc error during reconfigure

Signed-off-by: Hadrien Boutteville <hadrien.boutteville@gmail.com>
libgtk3: add two patchs and disable gdk backends for host-libgtk3

Signed-off-by: Hadrien Boutteville <hadrien.boutteville@gmail.com>
libgtk3: add patch to reduce dependencies for host-libgtk3

Adapted from the patch of libgtk2. Disable all backends for
host-libgtk3.

Signed-off-by: Hadrien Boutteville <hadrien.boutteville@gmail.com>
libgtk3: add XInput dependency

From NEWS file in "Overview of Changes in GTK3+ 3.3.18":
XInput2 is now required for building the X11
backend, support for XInput1 has been removed

Signed-off-by: Hadrien Boutteville <hadrien.boutteville@gmail.com>