(#1278) - pass errors back from ajax requests
(#1308) - Support 'key' in allDocs()

Currently allDocs doesn't correctly support
the 'key' param.  This is reproducible
in all 3 local adapters and the remote
http adapter.  This fix adds 'key' support
plus some tests to verify it's working.
(#1315) - Use `open_revs` to fetch missing revisions in one go.
(#1210) - Fix attachments in websql/Safari

Fixes problems we encounter with unexpected
encoding coercions for non-text attachment
data.
(#1307) - Test replication of empty database
(#1302) - switch to mocha
add cancel to api.sync and update stale issue 838 work
replace custom clone with utils.extend