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.
Machine join/remove v2 API.
bump(github.com/goraft/raft): 6bf34b9

Move from coreos/raft to goraft/raft and update to latest.
Merge branch 'master' of https://github.com/coreos/etcd into proxy

Conflicts:
	config/config.go
	server/peer_server.go
	server/transporter.go
	tests/server_utils.go
Merge pull request #582 from benbjohnson/proxy

Proxies & Config API
fix(tests): pass all tests using latest raft