Make icons and titles work like on X

Make icons and titles work like on X

* pgtk-win.el (frame-title-format, icon-title-format): remove.
* pgtkfns.c (pgtk_set_name_as_filename):  remove.
* pgtkfns.c (pgtk_set_name_internal): remove gtk_window_set_icon_name call.
* pgtkfns.c (pgtk_set_name): change value of update_mode_lines.
* pgtkfns.c (pgtk_explicitly_set_name):
prefer the symbol to an immediate value.
* pgtkfns.c (pgtk_implicitly_set_name): remove pgtk_set_name_as_filename call.
* pgtkfns.c (x_set_icon_type, x_set_icon_name): re-port from X code.
* pgtkfns.c (xg_set_icon, xg_set_icon_from_xpm_data): port from X code.
* pgtkterm.c (pgtk_bitmap_icon, pgtk_text_icon, pgtk_create_terminal):
port from X code.
* pgtkterm.h: add function declarations.