Ducky docs generation

Now, if you run `jake docs` in the root of the player, JSDuck will scan `./src/` directory for javascript files with documentation and put the generated result into `./doc/api/` directory.
I'd like to mark private methods and functions somehow, here it's not so important and underscores may be removed, but in API, I'd like users to see which functions are safe for them to use, and which are not. Though we may move private functions into some private namespaces or closures, then underscores will be gone.