Remove use of xtend

This patch converts RuntimeCodeGenerator into pure Java, optimizing it
in the process a bit. Since this is the last piece of Xtend code in
controller, also remove any trace of xtend.

Change-Id: I462968202d0e26c852aa683905b97bab8c5f99cf
Signed-off-by: Robert Varga <rovarga@cisco.com>
Merge "Remove use of xtend"