do not abort silently when libzypp init fails (bnc#887089)

- 3.1.94
Merge pull request #136 from yast/sw_mgmt_error_handling

do not abort silently when libzypp init fails (bnc#887089)
improved "skip registration" label (bnc#888561)

- 3.1.95
Merge pull request #137 from yast/skip_label

improved "skip registration" label (bnc#888561)