adhere to couchdbkit 0.6.2+ hightened strictness on doc types in view results

(is backwards compatible with 0.5.7)
explicitly pass in wrapper class to SubmissionErrorLog.view

for couchdbkit 0.6.2+ compatibility
override MobileBackend.view to happily wrap anything

for 0.6.2+ compatibility
use explicit wrapper instead of a hacky classes thing
Merge pull request #1081 from dimagi/couchdbkit-0.6.4

Fix tests for couchdbkit 0.6.4