Issue # 459 fix. Test should be made
Issues #459 and #500 fixed
Issue #502 fixed
merge with development
Merge pull request #501 from Bohdan-Tereta/development

Issues #459 , #500, #502 fixed
Issue #499 fixed
Merge remote-tracking branch 'upstream/development' into development
Issue #416 done. Migrations regenerated.
Merge pull request #505 from Bohdan-Tereta/development

Issue #499 fixed
Merge pull request #508 from AnnaStorozhenko/development

To issue #446, completed
To issue #493