[IMP] product: remove UoM constraint from product module and give it in stock and account module

Closes #2440
[IMP] web client refactoring: action and view manager

large rewrite of action manager, view manager and
viewmanageraction.  The goal is to lay the foundation
for the redesign of the advanced search view.

This commit includes:
* improvements to the display order (no/less flickering)
* large simplification of the breadcrumbs code
* much better html layout for the header (no table)
* bootstrapisation of the view manager
* lots of optimizations/simplification
* a base.css.map, courtesy of the last sass version
[FIX] fixes many issues with the various views

the views don't always return a proper promise, or were
somewhat fragile and broke with the changes in the view
manager.
[IMP] readd pager functionality to web client

The pager was removed in the refactoring of view manager. This commit
readd the pager, and improves its rendering to avoid flickering
[IMP] graph view integration into view manager header
WIP
css tweaks
css tweaks
work on searchview
wip
work
work
work
work