doc: fix documentation of POST /v2/admin/members
etcdhttp: separate member create deserialization
etcdhttp: properly serialize Member on POST
etcdhttp: only log when error deserves it
etcdhttp: 415 when content-type not JSON
Merge pull request #1463 from bcwaldon/writeError-logging

etcdhttp: only log when error deserves it
httptypes: test HTTPError
httptypes: set headers before call to WriteHeader
main: catch a few unhandled errors

If any of this initialization fails, something very bad has happened,
and we should not continue as-is (this has previously manifested in
strange bugs)
Merge pull request #1466 from jonboulle/errors

main: catch a few unhandled errors
Merge pull request #1464 from bcwaldon/error-ctype

Set Content-Type before calling WriteHeader
Merge pull request #1465 from bcwaldon/member-post

Clean up POST /v2/admin/members
Add Skydns, crypt, viper

Added a plethora of tools we've written or contributed to that use etcd.
Merge pull request #1475 from bketelsen/patch-1

Add Skydns, crypt, viper
raft: add tests based on section 5.2 in raft paper
Merge pull request #1471 from unihorn/189

raft: add tests based on section 5.2 in raft paper
etcdhttp: encode MembersCollection properly