Trigger profiler on longer frames

[tehKaiN]

Suppose I'm making a 50fps game and it works 99% of time, but sometimes stuff executes longer due to unfortunate branches taken. It would be extremely cool to have some kind of way to inspect this.

Best solution (possibly related to #105):

• make special mode where profiler starts to collect data as the game is running until canceled (watch out for memory/disk usage)
• stop execution and show the graph if last frame exceeded desired execution time of game loop
• bonus points if that special mode can be disabled/enabled in code (e.g. when asset loading has ended and game loop starts)

Not-so-good-and-probably-cumbersome-but-acceptable solution:

• I'm coding a game so that it can replay inputs and replay is deterministic
• somehow I get notified from the emulator that last frame execution took longer than expected
• I change my game code and rerun it so that it triggers a profile on start of problematic frame

[BartmanAbyss]

Let me think a bit on this...