Upgrade poor handling of missionSchedule in init_OB

currently, init_OB searches relative filepaths for some OB.csv file specified by the missionSchedule attribute.

This was implemented this way to enable scriptfiles to point to a general "OBXX.csv" when automatically generating large numbers of scripts with makeSimilarScripts.py

Implementation should include full filepaths. -> also upgrade makeSimilarScripts at the time this is addressed.