Make gir files depend on their library

Otherwise with parallel builds we might try to build gir files
before the library causing an error. This happened once in the
buildbot.

Fix #4606
Fixes #3665: add is_fullscreen() method to Window class

Signed-off-by: Diego Naula <dnaula1997@gmail.com>
Merge branch 'gir' of https://github.com/dnarvaez/sugar-toolkit-gtk3 into dnarvaez-gir
Add single_instance field to activity bundle
This field can be used by activities that need to be restricted to a
single open instance. Usage is:

single_instance = yes

jarabe/model/shell.py has been modified look for this field in a
separate patch to Sugar.

Together these two patches constitute the implementation of Sugar
feature Launch Limits [1]

[1] http://wiki.sugarlabs.org/go/Features/Launch_Limits