Added jquery-ui javascript to be able to use draggable/sortable events
Added row handler (for drag&drop) and data-informations

data-informations are here to be able to know if we can drop a skill
somewhere (because of dependant skills and levels) so we can recalculate
the placement before we save it. (This way, we can prevent useless
server calls)
Making the row sortable with an handler

adding a css style for sortable handler.
view.skillplan: changed loop to only use values as we don't care about keys.
Added the parents in each entry for js use

- highlight parents / children
- checks when sort skills