Rewrite of validation error messages to suit mockup.

Due to limitations in the validation plugin, and in the interest of forward compatability with updated plugin versions, this commit includes changes to error message structure which affects CSS:  Previously stacked classes sharing .message between .info and .error have been separated.
	
Old format:
	<div class="message error"><span>etc

New format:
	<div class="message"><span class="error">etc

Similarly with .info - remove .message class from .info html