see #4429 - Right click menu "undo, cut, copy, paste, delete, select all" for each text component (originally based on patch by NooN)

git-svn-id: http://josm.openstreetmap.de/svn/trunk@5886 0c6e7542-c601-0410-84e7-c038aed88b3b
Merge branch 'master' into mirror