Corrected bug in multiprocess causing deadlock at exit

Multiprocess debugging messages now use one color per process
Corrected RemoteGraphicsView not setting correct pg options on remote
process

New debugging tools:
* util.cprint for printing color on terminal (based on colorama)
* debug.ThreadColor causes each thread to print in a different color
* debug.PeriodicTrace used for debugging deadlocks
* Mutex for detecting deadlocks