Fix jQuery UI dateFormat conflict

Fixes issue with Dates not being parsed correctly when using a date that new Date() doesn't understand!
Update jquery.tablesorter.widgets-filter-formatter.min.js
LESS theme update for LESS 1.4+
Added group-separator option
Added file type parser
Ensure resized headers have data stored, or provide a fallback - fixes #394
better formatFloat replace method
allow sorting zero value hex (0x00)
Added pager countChildRows option. See issue #396
version bump
removed change event, fixes #400
updated readme & docs