ref #8238 Remove too specific generics from TermTree and TermNode
ref #6794 adapt TaxEditor to new term structure (rename FeatureNode and FeatureTree)
ref #8162 move FeatureTree and FeatureNode to new term package in TaxEditor
Rename utility method
ref #7923 Extract common interface for feature tree editors
code cleaning
ref #6806 Fix dirty state handling and saving in feature tree editor
Ask for saving before executing operations
ref #6806 Implement operation framework for feature tree editor
ref #6746 Add "Create Feature Tree" menu item
ref #6746 Hide menu items when nothing is selected
ref #6746 Add/adapt handlers for feature tree editor