IUCV-Terminal-Server - only pass along group changes

Yast EditGroup method only requires the actual changes, not the whole group object.

Fixes bnc#870891
IUCV-Terminal-Server - Reset groups before adding new ones

As suggested in bnc#870891 it is recommended to run ResetCurrentGroup before adding new ones.
Bump version to 3.1.11 and update changelog
Merge pull request #16 from thardeck/fix_bnc316378

Fix bnc870891