Add context menus for morph, relation and depTree
Add ability to disconnect or move nodes to root
Update context menu styling
Remove console logs
Minor style changes for context menu
Insert empty lines in contextMenu code
Update context menu directive

Listens to user defined click events, position can be configured
Nested dropdowns by pure css
Add nesteMenu directive in relation
Start to use a nested dropdown to select relations
Remove obsolete code
Nested relation label menu working
Calculate an ancestor chain for nested tagsets
Add nestedMenuCollection directive
Refactor nestedMenu handling
Define a property to change in nestedMenu
Minor fixes to nestedMenus

They are more flexible within the relation plugin now, but harder to
reuse elsewhere - which is probably ok. We'll see.
Could also be that we need the same behavior in other places too.
Add a nested class for nested menus
Add an arrow right image for menus
Add style to nested dropdowns