replaced if with switch
Scoring prototype; made track height and width global, use them in several classes
Blue gem is now rendered randomly on board
Gem collision detection, score update when reaching gem
Deleted Blue Gem file with space
Added inheritanse to Gems types. Fixed problem with position of bugs and collision detection
More precize Gem pick detection
Added dt multiplier, refactored gems colliions, added blue gem, moved gems objects into array
Added div with score count
Some comments and dt multiplier
Speed adapted for dt multiplier
Done comments for app.js
Completed readme
In engine.js updated variables calls (from properties to globals)
Done comments for engine.js
One var for all objects initialisation
Merge pull request #1 from korneevaed/master

Gems, documentation and improvements