Fix class names as per code review.

See https://github.com/msweeney/yui3/pull/1 for details. This commit does the following:
- yui3-form-inline is now the default form. The previous default form is yui3-form-stacked.
- Adds input sizing with a naming convention similar to YUI grids.
- Form labels are display: inline by default. They are display: block for checkboxes and radio buttons, and for specific form implementations.
- Rename yui3-form-horizontal to yui3-form-aligned
edit test with new classnames