Replace all mentions of soldat with opensoldat after rebranding

[Shoozza]

The free and open source version of soldat is now called opensoldat to distance itself from the commercial version of soldat which was acquired recently and seems to become proprietary with a new rewrite.

In order to make sure people can differentiate between the commercial and the floss version a renaming was necessary.

All mentions of soldat in the application should therefore mention opensoldat instead.