functions and move that code into separate *_load_*() functions (#475565).

* gtk/gtk.symbols, gtk/gtkpagesetup.c, gtk/gtkpagesetup.h:
Extract gtk_page_setup_load_file, gtk_page_setup_load_key_file,
gtk_print_settings_load_file and gtk_print_settings_load_key_file.
Change the matching *_new_*() functions to use those functions.

svn path=/trunk/; revision=19176