change all control button from text display to icon,
plus some css and layout fixes
two crossword load bugs fixed:
- if a crossword had been rezized before reload, the markers would shift
- data bindings for words were broken after load of saved words
- plus minor syntax error in test json data
modify qantic.angularjs.stylemodel for IE8 issue:
make sure size change does not trigger letter marking
multiple browser compatibility issues:
- css IE8 issues
- catching of default events for special keys only works in keydown
  for most browsers, while letter identification reliably works only
  with keypress