Defining G_DEBUG=fatal-warnings is useful for debugging, but it causes
the build to fail due to asserts during vapigen.
Unset G_DEBUG before calling vapigen.
Signed-off-by: Thomas Haller <thaller@redhat.com>
This patch adds the autotools facilities to generate vapi files so that
libnm-util and libnm-glib can be consumed from Vala.
It depends on vapigen and it is a soft dependency.