(#72) - more helpful error message for ddoc view
(#101) - increase test timeouts

These tests are slow in Safari, and I'm tired of
re-running them.
(#103) - use same md5 function as PouchDB
(#113) - travis
(#105) - batch the persisted mapreduce updates

This batches the updates fetched from db.changes()
to a max batch size of 50 (may change later) in order
to avoid reading every document into memory.