Update .gitignore
Update .gitignore

- Ignore *.o, backup files, and generated Makefiles in all subdirectories
- Ignore *.pyc files.
- Do not ignore .gitignore, we actually want to track this.

davidmalcolm/pygobject,davidmalcolm/pygobject,davibe/pygobject,davidmalcolm/pygobject,sfeltman/pygobject,choeger/pygobject-cmake,jdahlin/pygobject,GNOME/pygobject,davibe/pygobject,jdahlin/pygobject,thiblahute/pygobject,MathieuDuponchelle/pygobject,MathieuDuponchelle/pygobject,sfeltman/pygobject,thiblahute/pygobject,choeger/pygobject-cmake,davibe/pygobject,pexip/pygobject,pexip/pygobject,sfeltman/pygobject,jdahlin/pygobject,GNOME/pygobject,thiblahute/pygobject,davibe/pygobject,GNOME/pygobject,choeger/pygobject-cmake,MathieuDuponchelle/pygobject,pexip/pygobject