datastore: runQuery(stream mode) - use limit(n) logically - fixes #296
Merge pull request #297 from stephenplusplus/spp--datastore-stream-limit

datastore: runQuery(stream mode) - use limit(n) logically - fixes #296
storage: support resumable uploads
add regression test
add some unit tests
lastByteWritten -> numBytesWritten
- 5mb file, + 3 mb file
upgrade mocha + reorder tests
exponential backoff