SERVER-13795 rename test binary to dbtest
SERVER-13797 Remove more usages of Client::getContext

This change removes additional usages of Client::getContext and replaces
them with passing the database directly.
SERVER-13820 prevent updateUpstream from using a null connection
SERVER-13817 removing GhostSync
SERVER-13821 privatize SyncSourceFeedback's resetConnection()
SERVER-13823 remove magic from RSBase
more rollback4.js debuggery