* Add repo-sync-releases admin command
Will help recovering corrupted database, see #3247
* Load repos in chunks of 10, exit with error if unable to get a list, scan private repos, fix typo
* Fix debug output about num releases
* Introduce RepositoryListDefaultPageSize constant, set to 64
Use it from the new admin command
* Use RepositoryListDefaultPageSize in more places
* Document RepositoryListDefaultPageSize