basic implementation of issue #2
by feel, best performance, changed immediateRender to true, springStiffness to 7 - issue #2
cant set blendTime to 0, causes strange behavior in navigator and lip tile sources. should have made the basic config changes in #2 and #3 in a diferent branch related to #4. will do before pulling
reverting a couple changes to core openseadragon options unrelated to issue #2 . will explore these in #4 were they have already been referenced.
blendTime needs to be equal to animationTime to avoid blurred images
correcting comment per ventero's review
refs #22 use Math.pow per houseofyin and memoize implementation of getLevelScale per acdha
Merge pull request #25 from openseadragon/requestanimationframe

Requestanimationframe
Merge pull request #26 from openseadragon/memoizelevelscale

memoize default implementation of getLevelScale
niave implementation of prerender for canvas, the first optimization discussed here: http://www.html5rocks.com/en/tutorials/canvas/performance/
improved caching follows existing use of tile.unload to delete prerendered canvas
what was initally a feature branch to work on just canvas prerender, evolved into a feature branch focused on broader ideas discussed in issue #4 - I've basically been able to reduce time spent in drawTile by half. good stuff, thanks to dustmoo for getting us looking into this
merging, not sure why I get a conflict on this, must be doing something wrong in my work flow