Refactor and fix canvas tile layer renderer
Clear tiles that are not fully covered
Merge pull request #518 from elemoine/canvas

Canvas tile layer renderer occasionally glitches when panning fast
Add full screen control
Use full screen control in full screen example
Toggle css class and use css content for anchor
Fix full screen button state
Hide the control if the Fullscreen API is not supported
Merge pull request #521 from openlayers/full-screen-control

Full screen control