Renamed skillPrerequirementEditor as skillEditor
Fixed a bug in skillEditor

A newly added prerequirement is now correctly shown in search results
when current target skill is changed.
Fixed Competence names to be shown correctly in skillEditor
Merge branch 'master' into skill_editor
skillEditor: Added a string indicating CompetenceNode type
Small skillEditor localization improvement
skillEditor: Improved fields in edit skill modal
Added loading icons to skillEditor
Fixed a couple of bugs in skillEditor

The skill editor now correctly removes a node from displayed nodes
if the last prerequirement skill is removed.
Added skill deletion confirmation modal to skillEditor
Added error notification box for search results in skillEditor
Added target node loading error notification box to skillEditor
Externalized and localized skillEditor failure messages
Polishing login layout
Added titles to views
Improving navigation
Making course graph work in positioned divs
Make graph view detect cycles
Move the skill prerequisite editor to a partial in order to ScopedCourse and Competence share it
Adding icons and titles to skill prerequisite editor