Selecting missing pattern will only Report.Error

- Instead of raising an exception
- bnc#875799
- This change makes it possible to continue even if some of the patterns are missing
Adapted test case
Changes and version
Adapted text of the error to make Josef happy :)
Hopefully even happier
Merge pull request #48 from kobliha/selecting_missing_patterns

Selecting missing default pattern changed from exception to reported error
display a global checkbox when selecting an add-on during registration (bnc#870625)

- 3.1.14
refactored widget labels
Merge pull request #49 from yast/addon_checkbox

display a global checkbox when selecting an add-on during registration
fixed wrong constant name resulting in a crash during installation

- 3.1.15
Merge pull request #50 from yast/const_fix

fixed wrong constant name resulting in a crash during installation
removed dead code
allow setting the dialog title and display an optional heading
do not close the dialog in running system
changes

- 3.1.16
Merge pull request #51 from yast/addon_eula

Enhancements needed for registration addon EULAs