Inherit banner settings from parent Spaces.
Inherit colorizer settings from parent Spaces.
Fixed exception when Space doesn't exist.
Use oa_core_get_parents() rather than directly accessing the field (and made a minor change to prevent crashing if the space doesn't actually exist).
Merge pull request #27 from dsnopek/oa_appearance-sub-spaces

Inherit banner and colorizer settings from parent Spaces.