Don't use minifiable player methods in fullscreenToggle

Use string literals to lookup fullscreen-related methods on the player object in the fullscreenToggle component. Otherwise, closure compiler replaces them with minified method names and makes it impossible to supply a simpler "player" object with customized fullscreen logic for the fullscreenToggle to interact with.

This PR includes a typo fix and the changes from Pull #850. I can open a clean PR if those changes require re-think.