Add webclient based on Charisma
Major unfinished refactoring
Major ongoing refactoring and new code.  Full revamp of block handling and data type system
Completed major refactor and new block handling and data type system.
Fix RPC.  Add 'log' command.
Reworking block handler
Fixed memory issue by creating block handlers during 'serve' initialization instead of on-demand and per versioned service.
Fix artifact produced by incorrect use of leveldb iterator.
Fix XZ reconstruction
Update documentation.  Remove cache package until ready for LRU cache rewrite with periodic, sequential writes.
Add jpg with desired quality support.  Add make support for uuid and websocket
Allow dvid to start without valid webclient specification
Document build process and add Go snappy to dependencies
Add serverless run mode that opens datastore, runs command
Make initial config a dvid Volume struct usable from other programs.  Minor fixes.
Modify packaging for labels32 and labels64 data types
Add stride to more robustly handle JPEG input files
Fix data set name handling.
Minor mods for readability and removing unnecessary debug printouts
Add block op graphs and update image browser page in webclient