clutter-text: prevent reset of user set font descriptions on dpi changes
clutter-text: prevent reset of user set font descriptions on dpi changes

When setting the font using clutter_text_set_font_description(), the
font settings on a ClutterText actor can be reset when there is a dpi
changes signaled by the backend.

https://bugzilla.gnome.org/show_bug.cgi?id=702016

GNOME/clutter,jigpu/clutter,Distrotech/clutter,GNOME/clutter,djdeath/clutter,Distrotech/clutter,djdeath/clutter,Distrotech/clutter,djdeath/clutter,djdeath/clutter,jigpu/clutter,GNOME/clutter,djdeath/clutter,Distrotech/clutter,jigpu/clutter,jigpu/clutter,jigpu/clutter,jigpu/clutter,ebassi/clutter,djdeath/clutter,ebassi/clutter,ebassi/clutter,Distrotech/clutter,Distrotech/clutter,GNOME/clutter,ebassi/clutter,GNOME/clutter,ebassi/clutter