firefox 44.0.2 won't start: error from libgiofam.so

[Winston]

The original problem was:

   After "pkg upgrade firefox" from 44.0,1 to 44.0.2,1,
   firefox won't run.  It exits with:

   /usr/local/lib/gio/modules/libgiofam.so:
       Undefined symbol "g_local_directory_monitor_get_type"

New information:

* Doing "pkg upgrade" (everything) and rebooting didn't fix it.
  (Same error.)

* Doing "pkg delete gio-fam-backend" deleted gio-fam-backend and
  xf86-video-radeonhd without complaint.

* Restarting X11 after deleting those packages worked well without
  complaint.

* Starting firefox then did something different: it popped up a small
  box giving me the choice of starting in "safe" mode or retrying.  I
  chose "safe" mode.

Since that time, firefox appears to be working normally again, even
after stopping and restarting.

HTH,
 -WBE