Central tests failures on Luna

There are the following issues:

• the o.e.e4.rcp feature is required (https://github.com/jbosstools/jbosstools-build/pull/127 hasn't been applied yet)
• the examples tests require the o.e.help.ui plugin when opening the Cheat Sheets view
• the central tests freeze with GTK 3. GTK 3 seems not to be stable. See http://download.eclipse.org/eclipse/downloads/drops4/S-4.4M3-201310302000/news/#Platform. The tests pass with GTK2
  It is possible that some other components have a similar issue.

Fred's fixes for the conversion and configurator plugin work correctly.

I have tested these issues on Linux and Windows.