Fixing up examples:

/src/rita.js:
- Re-enabled RiText.defaultAlignment
- Added RiText.prototype.color() as used in www/examples/canvas/simplest.html
- Added RiText.showBoundingBox()

/www/examples fixes:
- simplest.html (was making unsupported RiText().color()... call)
- grammar-haiku (both canvas and processing versions needed fixing)
- alignments.html (canvas ver. making Processing calls, invalid call to show boundingbox)