Add #includes needed with the latest glibmm.

* gdk/src/color.hg:
* gdk/src/pixbuf.hg:
* gdk/src/pixbufanimationiter.hg:
* gdk/src/pixbufformat.hg:
* gdk/src/rectangle.hg:
* gdk/src/rgba.hg:
* gdk/src/types.hg:
* gtk/gtkmm/object.h:
* gtk/gtkmm/stock.cc:
* gtk/gtkmm/stockid.h:
* gtk/src/border.hg:
* gtk/src/enums.hg:
* gtk/src/main.hg:
* gtk/src/papersize.hg:
* gtk/src/textattributes.hg: Add individual includes now that gmmproc does not
add #include glibmm.h at the top of every generated header.