Improve fabrik plugin

Use $config for config instead of $shim and simplify code  a little.

Highlight potential logic issues where $config is set and $js is blank -
but not sure I understand enopugh to change this..
Change page init trigger

Change page init trigger from fabrik.loaded event (which is triggered at
the end of fabrik.js being loaded) to a requirejs so that we can be
certain that tips.js has loaded before initialising tips.

(i.e. requirejs is really a better approach than using the trigger).