Fix Overlapping Skills and Videos and Added new ways to add skills

[https://www.pivotaltracker.com/story/show/67380924](Pivotal Tracker Story 1)
[https://www.pivotaltracker.com/story/show/67380958](Pivotal Tracker Story 2)

* Now you can add skills using Tab, Comma and Enter Keys
* Fixed CSS Bugs on Users show page where Skills and Videos were Overlapping