1. This should fix Issue 1625 (Bizarre Auto Frame Limit)

Now the frame limiter yields on CPU thread, not as before on GPU thread mistakenly

2. Fixed clear of VI interrupts
   I guess VI interrupts are not used at all, because they were never cleared before

3. Made GPU thread 0% processor usage when paused whatever your active config is.
   I tried the event approach but somehow the thread resume latency is excessively long (Who can tell me why?)

git-svn-id: https://dolphin-emu.googlecode.com/svn/trunk@4790 8ced0084-cf51-0410-be5f-012b33b47a6e

Source/Core/Common/Src/Timer.cpp

@@ -78,7 +78,7 @@ void Timer::Update()
 // -------------------------------------
 
 // Get the number of milliseconds since the last Update()
-s64 Timer::GetTimeDifference()
+u64 Timer::GetTimeDifference()
 {
 	return(timeGetTime() - m_LastTime);
 }