Delay GPU signals and waits to simulate cycles.
Make sure lists aren't reused before they complete.
Slow down the GPU clock estimate.

This makes  Fat Princess for example much faster.
Don't allow two drawsyncs to be in play at once.
Use regular events for GPU for now, quicker.

There's too much latency in threadsafe events, causing tests to fail.
Might break games too.  I guess they need to execute more often...
Merge pull request #1213 from unknownbrackets/dlist-cycles

Try to match GPU cycles to the CPU