Merge pull request #49 from Eye-Static/zach

fixed above-words glitch
remove redundant code, add error dialog (instead of alerts), change styling slightly
remove useless function, refactor minor ref to proper place
speed-up page, run npm install first
Update validator.js
enlarge game area, simply css
remove redundant css
Merge branch 'master' into andy
slightly increase speed by reducing DOM accessing
fix minor tray drop bug
major speed improvement, one display bug yet to fix
fix more bugs, refactor board.print functions, delete now unneeded funcs
fix phantom letter bug, only revert bug remains
change dead class to id for minor speed improvement
fix revert bug, finally
Merge pull request #50 from Eye-Static/andy

Major speed improvements and some refactoring
fixed single-letter error