CXX-143 remove src/mongo/s

haveLocalShardingInfo
 - never called (mongos specific)

createDirectClient
 - never called (removed from interface as DirectClient is only used interally by the server

getAllShards
 - never called (mongos specific)

isAShardNode
 - never called (mongos specific)

ResultFlag_ShardConfigStale
 -  irrelevant to driver (mongos specific)