misc bug fixes

Ran some testing on a variety of browsers and found/fixed bugs:
* use e. instead of event. in event handler (broken in firefox)
* canvas: use lineWidth, strokeStyle, fillStyle (broken in firefox)
* replaceHtmlBlock, deleteHtmlBlock should use parentElement now that we have a setParent() API
* change debug console styles to make it look more similar in firefox, safari, and chrome