Added Tern and Acorn libraries
Basic implementation
Loading only for js, customise css and fadeout
Added functionality to start tern server and load definitions
Added complete url to files
Removed old hint and connected Tern to tab keybinding.
Functionality when Tern is disabled
Removed emmet key handlers from javascript panel and fixed autocomplete function accordingly.
Removed emmet toggle comment for javascript and implemented the CodeMirror one.
Changed tooltip appearance to jsbin style.
Added feature flag and moved the functionality to its own file.