Add version requirement >= 2.60 for the GLib family of libraries
Add version requirement >= 2.60 for the GLib family of libraries - due to usage of Reference-counted-data in lib/wptoml/array.cpp (requires >= 2.58, see https://developer.gnome.org/glib/stable/glib-Reference-counted-data.html) - and usage of G_GNUC_FALLTHROUGH in lib/wp/object-interest.c (requires 2.60, see https://developer.gnome.org/glib/stable/glib-Miscellaneous-Macros.html#G-GNUC-FALLTHROUGH:CAPS)
Signed-off-by: Martin Koch, ESE GmbH martin.koch@ese.de