Refactoring. Configuration and RescueFile moved to libgame
RescueFile method will be needed by some plugins (formats)
to get files that can not be determined as dependency
(ie: path writting in its data)

Configuration xml file has been merged to xml Edit since it
contains the configuration of the current game modification.
It has been moved to libgame to be accesible by plugins.

* Configuration.cs: Fixed bug getting Nitro.Rom format
* Worker.cs: Fixed bug not resolving path at Import method