Tokens are similar to sessions in that they stand in for users, but the
protocol handlers will manage them; Fever login hashes are the
originating use case for them. These must never expire, for example,
and we need to specify their values.
This commit also performs a bit of database clean-up
This required adding the "notes" column to the arsse_marks table and adding same as a target value in Database::articleMark()
The Context class was also adjusted to remove the possibility of false positives in some tests
- Backend functions for adding, listing, removing, and editing (renaming) labels currently implemented
- TTRSS functions for adding (fixes#96), removing (fixes#97), and renaming (fixes#98) labels currently implemented