[gtkmm] New pack_start()/pack_end() API:

[Murray Cumming <murrayc usa net>]

OK, I think this was worthwhile. Please don't hate us for changing these
methods _again_, but tell us quickly if you think it's wrong:
http://www.gtkmm.org/gtkmm2/reference/html/classGtk_1_1Box.html#a4
I have at least added back the old bool, bool overrides, so life is easy
for those who have not yet ported to gtkmm2.

Gtk::Table and Gtk::Paned are unaffected by this change.

-- 
Murray Cumming
murrayc usa net
www.murrayc.com