giiMTInit - Make LibGII thread-safe
giiMTInit sets up LibGII so that it is fully thread-safe. This allows
the application to call LibGII functions (on the same input) without
doing its own locking. This will enable extra checks and locks that are
off by default to avoid overhead.
This function does not replace giiInit(3), which must still be called
at least once.
giiMTInit returns 0 on successful execution.
This function has not been well tested.