ext/: update of cairo-based timeoverlay to 1.0 Cairo API doesn't work yet for resizing of output sink

Original commit message from CVS:

* ext/Makefile.am:
* ext/cairo/Makefile.am:
* ext/cairo/gstcairo.c: (plugin_init):
* ext/cairo/gsttextoverlay.c: (gst_textoverlay_change_state):
* ext/cairo/gsttimeoverlay.c: (gst_timeoverlay_update_font_height),
(gst_timeoverlay_setup), (gst_timeoverlay_planar411):
* ext/cairo/gsttimeoverlay.h:
update of cairo-based timeoverlay to 1.0 Cairo API
doesn't work yet for resizing of output sink