add rules to html (not shown, yet)
Put game state into URL
Merge remote-tracking branch 'upstream/master'

Conflicts:
	www/index.html
proper resizing in browser
detect draw games
Add license file; move cssshake styles into css file
ignore invalid moves for undo stack
properly display castling
show rules
top bar styling
new game menu
Show thinking (progress bar animation is stuck. Use worker?)
put difficulty into URL
add shuffle mode
update gh-pages
show messages again
play as black
put player color into URL
gh-pages do not belong in this branch
fix board orientation when switching color back and forth