Solve openSUSE 12.3 conflict before bootstrapping.

Because `patterns-openSUSE-minimal_base-conflicts` conflicts with `python`, lets remove the first one.
Fix undefined variable `BS_ECHO_DEBUG`. Replaced tabs with spaces.
The script does not ignore the environment `PACKAGESITE` and also checks for `BS_SALTREPO` in env.
All internal variables are underscore prefixed.