WIP: empty db support
Switch to promise-only implementation for node 0.10 compat
Switch to promise-only implementation for node 0.10 compat

The direct port of the same code is an interesting benchmarking opportunity:

* c3f1b1f8 using generators & node 0.11 --harmony: 7400 req/s
* this commit using promises & node 0.11 --harmony: 7100 req/s
* this commit using promises & node 0.10 & es6-shim: 4460 req/s
Merge commit '4b25b63da' into promise_port

Conflicts:
	Verbs.js
	restface.js
Merge commit '6c972f20' into promise_port
More design considerations
Add rashomon backend