SERVER-15887 Add tests for ipv6 hostname parsing.

Closes #846

Signed-off-by: Benety Goh <benety@mongodb.com>
SERVER-14638: Move global sethbmsg into ReplCoord
SERVER-15869: Provide config version for each member in replSetGetStatus
SERVER-15867: primary should response to heartbeats as electable
SERVER-15880 AutoGetCollectionForRead should always free its collection lock
SERVER-15880 Delete path should not try to create database