Merge pull request #972 from rsvato/master

Merge pollers from 2.2.0
[RJA-2312][fix]: "Mark as Destroyed" menu item is disabled when instance is Busy
Merge pull request #975 from ddurnev/master

[RJA-2312][fix]: "Mark as Destroyed" menu item is disabled
[RJA-2301][feature] - Hypermedia links to attachments collection