[backend] add an easy way to force a full tree rebuild
[backend] fix _volatile cleaning if a volatile binary gets replaced
[backend] remove typo exposed by last commit
[webui] avoid crash on invalid tracker in patchinfo editor
[api][backend] log build duration

and use it for job progress estimation
[backend] fix buildhistory query with duration time
[webui] accept extra error handling in code check
[webui] Better management of usernames in markdown

 * Users with a dash (like 'yast-team') are now managed properly.
 * Users with two underscores (like '_nobody_') are not enclosed in <em> tags
[backend] report filename of bad files if the db is corrupt
[backend] implement first steps of package tracking
[backend] ignore bad entries if the gbininfo is out of sync

Otherwise we may die if gbininfo references vanished packages.
[api] fix migration numbering
[api] add initial binary tracking code
[api] add operation flag to binary tracking