Keyboard bugfix, minor improvements throughout

BUGFIX: love.keyboard.isDown always returned false
Added love.graphics.setTextAlign
Spline can now have an arbitrary number of points
Modified wave palettes to be the way they were meant
Added starfield demo, graphics and window additions

* The Rakefile now lints JavaScript files
* Grid and wave pass the (updated) `.jshinrc`
* Added some transformation functions to `love.graphics`
* Began implementing fullscreen mode [WIP]