style.css: remove unseen mergeconflict stuff, general cleanup, use assets.tchncs.de for font-awesome+bootstrap

temporaly changes: PageTitle Options (color+background-color), FilterMenu (color+background-color+padding), BoxCategories (heading color), Profiles got a background

This reverts commit 2e9f5155.
It was wanted in /testing branch.

navbar is now fixed on top, gave it a provisionally padding and changed the footer to our preference

Temporary fix for menu collapse on mobile devices

Add node modules and bower components to gitignore

This is sort of temporary fix, that will work until vanilla updates its jquery, so that all bootstrap code could be supported. This proved to be working well with latest stable vanilla. Should fix #145, #146 and #150.

Make lang attribute depend on Vanillas locale

Replaced the fix "en" in html elements lang attribute with Vanillas current locale.