- isolate dependencies (both Git repos and ".nimble" dir) in "vendor"
- ensure that everything is compiled using our version of Nim with
something as simple as "make"
- pull the latest changes with "make update"
- re-create Nimble's package dir and re-build the Nim compiler automatically when needed
- "env.sh" script that can be used to prefix any command that needs to use
"nim" or "nimble" from our Nim repo
- move the top level nim.cfg to nimbus/nim.cfg so it doesn't apply to
deps
- "fetch-dlls" `make` target for Windows to get precompiled Snappy, RocksDB and SQLite DLLs
- added some useful `chronicles` defines in the top-level nim.cfg
- converted some assert() calls to error codes to avoid a reported
segfault with -d:release
- the recoverable errors are being recovered from, in persistWorkItem()
- the only case that's a show stopper raises an exception