Add proxy mode.
Proxy promotion.
Add automatic node promotion / demotion.
Add auto-demotion after peer inactivity.
Check for peer before demotion.
Fix JoinCommand comment.
Minor fixes.
feat(scripts/test-cluster): create three proxy nodes

This uses some sleep hackery to make sure that window 1 has followers
and window 2 has proxy machines. Seems to work!
Merge pull request #4 from philips/benbjohnson-proxy

feat(scripts/test-cluster): create three proxy nodes
Fix PUT /config response and log errors.
Merge branch 'proxy' of https://github.com/benbjohnson/etcd into proxy
Add /machines and /machines/:name endpoints.
Minor fixes to proxies.
Add minimum active size and promote delay.
Allow partial cluster config updates.
feat(benchmark) fix of flag arguments and updated logging
Machine join/remove v2 API.
docs(Documentation/api): fix JSON spacing, syntax highlighting
Merge pull request #641 from mdlayher/patch-1

docs(Documentation/api): fix JSON spacing, syntax highlighting
doc(api) correct release lock curl command

related to #638 issue - DELETE request body is ignored
typo fixed