Changes

Brings the VDM console of a launch to the front of the view

When a launch is made requesting an interactive session, the VDM console
does not always appear in the Eclipse console view. Instead the
Interpreter console is shown. This commit introduces a bring to front
call after the Interpreter has connected, thus its console should be
moved to the back.

Adds support for DBGP messages and Rmoves dead code

Some answers in the DBGP neither contain a property element nor a
success attribute, thus list is Null.

Checks whether the DBGP response has a value to print

Some of the commands executed in the launched interpreter return no
property value. (For instance a quit)