Merge pull request #491 from starwed/DelayName

Fix delay docs
Merge pull request #492 from starwed/2dfix

A few small fixes to 2D functions
Fix place()
Merge pull request #495 from starwed/iso-fix

Fix place()
Timing events

This patch measures the time between each important part of the loop:

* The length of each "EnterFrame" and "RenderScene" event
* The time Crafty waits from the end of one to the beginning of the next

The time since the last frame is passed to the "EnterFrame" event as the property dt.