Cleanup, Throttle JS, Lazy execute JS, Fonts

* Cleanup; removed old unused patches
* Implemented generic Throttle JS function to enqueue JS invocations
(already used it on reset_popup_dimensions)
* Lazy execute JS; now also accepts a function as a parameter
*  Widget extensions; put lazy loading in function, and enabled themes
to add to the action to load / overrule widgets of the framework (just
like plugins can)
* Fonts; moved all fonts to a generic place (nxsstyles), nxs menu
renders dynamic set of fonts