Merge pull request #19 from Eye-Static/zach

Zach
add board->board letter data transfer
all tile moving data bound
remove autoprefixer from build, caused problems
fix merge conflict
Merge pull request #20 from Eye-Static/andy

Data-binding finished (we hope), it's like sausages, you don't want to see how it's made
fixed tile-on-tile placement
Merge branch 'master' into andy
Merge pull request #21 from Eye-Static/andy

Tiles can no longer be placed on other tiles
add second player tray for local multiplayer, generalize board.retrieveLetter
add turn-taking logic, structure for two-player but not done yet
Merge branch 'master' into andy
Merge pull request #22 from Eye-Static/andy

Add some structure for local multiplayer
resolving conflicts