Clear unnecessary default Scintilla Ctrl-D duplicate keybinding.
Add SCI_DELWORDRIGHTEND command (patch sent to Scintilla ML).
Remove previous ScintillaGTK::KeyCommand override.


git-svn-id: https://geany.svn.sourceforge.net/svnroot/geany/trunk@1807 ea778897-0a13-0410-b9d1-a72fbfd435f5