use disable_refs (bug 919148)
Merge pull request #1181 from andymckay/919148

use disable_refs (bug 919148)
explicitly cache counts for collection listings (bug 912484)
Add header to API responses indicating whether the request was pinned to the master database
Merge pull request #1185 from chuckharmston/918124-collections_api_pinning

Add header to API responses indicating whether the request was pinned to the master database (bug 918124)
Allow deletion of Translations (bug 902435)