Label-aware annotations and Google cloud support
This release includes:
- Label-aware "annotations" datatype (used to be called "synapses")
- Google cloud storage engines for (1) google storage and (2) google bigtable. The google storage backend has been tested and tuned while bigtable is experimental.
- Labelvol merge caching so responses are immediate while actual merge at voxel-level is done asynchronously.
- Mutation of labelblk added versus ingest, i.e., the mutation will recreate associated sparse volumes.
- Various fixes.