Ctrl+E dialog is completely re-done using the approach used in
CycleBaseHandler. 
The user can filter over a table displaying a list of all the open
editors. 
This looks decent in dark theme also.
The filtered table can be transformed into a cyclable list just by
changing a flag.

Change-Id: Ifc2917557cffb55007615eef12e124f0506097de
Signed-off-by: Patrik Suzzi <psuzzi@gmail.com>