Based on !1 (merged).
libjcat-dev: Add missing -dev dependencies
Without these, building a trivial program against libjcat fails with errors like:
+ pkg-config --cflags --libs jcat
Package gio-2.0 was not found in the pkg-config search path.
libjcat-dev: Add missing dependency on a matching libjcat1
d/control: Enable gir debhelper sequence
Otherwise ${gir:Depends}
won't be generated.