ReGaHss: Implementation of 'system.Sleep(t)' function to suspend a script for t milliseconds

[jens-maus]

For some operations it might be useful to have a sleep like function that suspends execution of a script for a certain time interval. This new function could be system.Sleep(t) where the execution of a script is then interrupted for t milliseconds. Note, however, that a maximum time interval is required so that ReGaHss won't be blocked too long or otherwise a system hang could be a result.