LMS App - Student work disappearing after syncing

[frankyrumple]

Had reports of student work/files disappearing after syncing the LMS app. It was discovered that when some students open a word or excel document from the LMS app, it runs and opens the document from the LMS app cache directory. If a student does not use save as, then they are saving their work into the lms cache. This in turn causes the lms app to see the file is different and resync/download a fresh copy over the students work.

The lms app is NOT removing files from the student desktop or documents area.

Resolution - Force the student to save as somehow - e.g. read only, remove write/change permissions, or make a copy of the document in the students documents folder before opening it.

[jmichel-sbctc]

Potential fix for this is to impliment #144 as this would force students to save-as when saving a document opened from the LMS application. This would then avoid the issue where the cached files have the student's work, which then is overwritten when syncing.

[frankyrumple]

Code added to clear/set the read-only flag when downloading files from canvas. When opening files from cache, it forces a save as now.