Merge pull request #28 from hugo187/master

small fix of previous pull request
Merge pull request #29 from hugo187/master

just one more sql optimalisation
avoid erasing username when not providing during customer update
Merge branch 'master' of github.com:laposa/onxshop
add 6 columns layout
unify name convention Main Navigation vs Primary Navigation
change validation for limit_order_value from string to decimal
add CSS for 6 columns product list
simplify CSS for twoColumnLayout to improve nesting capability
use Onxshop Generic profile for AddThis
revert back twoColumnLayout rules
database optimalisation - added ecommerce_invoice_order_id_idx