g-ir-inspect: Inspect GI typelibs

Various distributions (mainly RPM based so far) make use of automatic
dependencies extracted from typelib files (they can require other typelibs
and also shared libraries)

Current features
* Print used shared libraries
* Print used typelib dependencies

Based-on-patch-by: Dominique Leuenberger <dimstar@opensuse.org>
Reference: https://bugzilla.gnome.org/show_bug.cgi?id=665672


Reviewed-by: Colin Walters <walters@verbum.org>
Signed-off-by: Dominique Leuenberger <dimstar@opensuse.org>
Signed-off-by: Igor Gnatenko <ignatenko@redhat.com>