Merge: Import studypaths with xml files, fixes #21

* issue21.1:
  Remove column last modified in studypath table
  Fix some issues with error handling of xml file upload
  Cleanup and proper implementation of default studypath
  excluded a not needed test file. deleted unuesed imports and unnacassary empty lines.
  Completed issue21.1
  added code for exception handling, that wont work
  added the feature of uploading xml files. Still missing: Exception handling
  made XML Interpretaion work. StudyPaths can now be read from XML Files. XML Files can NOT be uploaded from OLAT interface.
  update studypathmanager
  Studypath now supports od.fmi
  first changes to issue 21