Issue #73 Check to make sure Turnitin is enabled in current location.
Rubrics now being saved for PP assignments.
Merge branch 'develop' into feature/2014012408

* develop:
  Issue #73 Check to make sure Turnitin is enabled in current location.
All module check added to disclosure
EULA error moved to not show if previous submission has been made.
Version and docs updated.
Connection test added to cron event handler along with error message if submissions can't be retrieved in cron.
Specify assign when looking for user's grades (thanks to mattgibson)
Included gradelib file in cron if it hasn't been included already.
Scope of tool tipster anti-aliasing fixed to not affect whole of Moodle
No loger delete submissions from Turnitin in PP.
For post date hidden until date is used if set, if not then start date is used. If grades are hidden then post date is set in the future.
Cron functionality added to update post dates, post date is also now stored in config table
Ensure post date can't be before start date and remove setting of due date to 0 after it has been calculated.
Documentation updated and version incremented.
PHP header function replaced with moodle redirect function to fit with moodle guidelines
Fixed Oracle database error when getting forum post
Submissions are removed from the events cron if a student has not accepted the EULA.
Duplicate file declaration removed and submissiontype now used in correct context in PP file errors.
EULA reworked in PP and is now presented via an Iframe rather than a separate tab.