added paste event functionality, changed delete functionality to not take the document content into account as the text is in post-delete state
added patch functionality from Neil Fraser's diff-match-path; changed spyware to use patches
removed debug outputs
added a details field which describes the reason for change for source snapshots, added path information for files in source snapshots to avoid misundestandings with files with same name, changed character-level logging to add information on cases, when the changed file is new
Don't consider exercise downloadable if it's locked.
Revert pointless chmods.

This reverts commit c51385f90ab0e20f66443e4787e873b3a6cf580e.
(rm junk)
Error handling fixes and cleanups.
SourceSnapshotEventSource: document race condition