Removed some dead code from skillEditor views
Moved a helper method to ApplicationController

From plans/CompetencesController to ApplicationController
Improved Skill model to enforce and support position attribute
Implemented skill sorting for skillEditor using drag'n'drop
Fixed Competence model's 'users' association
Changed skillEditor to display 'move' cursor icon when skill is being dragged
Increased drag initiation distance in skillEditor
Changed skillEditor skill dragging to be contained within the parent div
Added move icon to draggable skills in skillEditor
Fixed a bug in skill deletion (skillEditor)
Removed a few global variables that were previously used for debugging