initial dialogs for addon product selection
command line mode is not supported
evaluate addon dependencies

automatically select the missing dependent add-ons
do not load repositories at runtime

we register _installed_ products only, no need to refresh and
load all available repositories
changes

- 3.1.19
Merge pull request #26 from yast/addons

Add and register Addons in installation (FATE#312925, FATE#315685)