More fixes on version 0.3.1

Here it comes a new version of PIM Xtreme: 0.3.1. It is mostly a fix version, so I encourage you to download it and install it.

The changes are:
* Add: posibility to Export and Import the System Configuration.
* Fix: error on adding an Event if there was no Event Types
* Fix: filtering Accounts (problem on groups)
* Fix: account sorting on Movement window
* Fix: adding task without priority, because you could delete all priorities (now you can't)
* Fix: modifying Movement Types
* Some translation fixes
* Some GUI fixes