* process.c: Add defined (HAVE_GSETTINGS) for xgselect.h

* process.c: Add defined (HAVE_GSETTINGS) for xgselect.h
(wait_reading_process_output): Add defined (HAVE_GSETTINGS) for
xg_select.

* xgselect.c: Add defined (HAVE_GSETTINGS).
(xgselect_initialize): Ditto.

* xsettings.c (store_monospaced_changed): Take new font as arg and
check for change against current_mono_font.
(EMACS_TYPE_SETTINGS): Remove this and related defines.
(emacs_settings_constructor, emacs_settings_get_property)
(emacs_settings_set_property, emacs_settings_class_init)
(emacs_settings_init, gsettings_obj): Remove.
(something_changedCB): New function for HAVE_GSETTINGS.
(something_changedCB): HAVE_GCONF: Call store_monospaced_changed
with value as argument.
(init_gsettings): Check that GSETTINGS_SCHEMA exists before calling
g_settings_new.  Do not create gsettings_obj.
Remove calls to g_settings_bind. Connect something_changedCB to
"changed".

Fixes: debbugs:8967