SERVER-5378 added tests for parsing map reduce output options
SERVER-5378 out {} parameters position independence

Where we put replace, db, inline, etc within the map-reduce "out"
BSON object shouldn't matter

Signed-off-by: Benety Goh <benety@mongodb.com>
SERVER-5378 replaced jstests/core/mr_parampositions.js with mr_test.cpp for out parameter field ordering