[ADD] FIXED create_from_ui inheritable to add more fields on order and payment
[MERGE] backend front end integration

Render the top-menu (backend menu or frontend editbar) server-side.
Use Fontawesome icons (mail, timezone, chat).
Refactor website widgets, split Website.editorBarin editorbar, ace, editorbar- content, editorbarCustomize.
[MERGE][IMP] Enable HTML in emails signature

Closes #801
Merge pull request #326 from hmen89/master

[ADD] point_of_sale: make the creation of orders and payment inheritable in create_from_ui method
[ADD]added feature of group by partner in the invoicing popup of contract(like in deliveries to invoice).