start of gtk 2.10 support

re-factored signals for better future support
added new_signal to gobject

Rev: src/post_modules/GTK2/Makefile.in:1.9
Rev: src/post_modules/GTK2/acconfig.h:1.8
Rev: src/post_modules/GTK2/pgtk.h:1.15
Rev: src/post_modules/GTK2/source/gobject.pre:1.7
Rev: src/post_modules/GTK2/source/support.c:1.12