Log Message:
Update to 1.99.17.

changes include:
* Threading support is compiled in by default now.  It is necessary
  to call gtk.threads_init() in order to make use of threading
  though.  There have been a number of fixes to the threading
  support too.
* Fix up some problems with multiple definitions of global variables
  in gobject module, that was causing problems on Mac OS X.
* Wrappers for many new APIs (John Finlay, Naofumi Yasufuku, Johan
  Dahlin and others).
* Improvements to the code generator to give better error messages.
* Some fixes to property APIs to work correctly on 64 bit systems,
  and to handle ATOM type properties.
* Fix copyright headers on source files.