Add functional blocks to playlab to set background, title, player speed, enemy speed.
touch up playlab functional blocks: remove _.partial; move installString to mathBlocks; eliminate extraArgs; touch up speed max/min logic.
move mathBlocks.js to sharedFunctionalBlocks.js
fix jshint
Merge pull request #312 from code-dot-org/playlab-functional-blocks

Add functional blocks to playlab to set background, title, and player/enemy speed.