if we call mongo_cursor_next() for the first time and there is no result, we should return MONGO_CURSOR_EXHAUSTED
adding comment
Changed _get_host_port to allocate memory returned dynamically using bson_malloc rather than using static memory to make mongo_get_primary and mongo_get_host thread-safe
Merge pull request #152 from fotonauts/return_exhausted

if we call mongo_cursor_next() for the first time and there is no result, we should return MONGO_CURSOR_EXHAUSTED
Merge pull request #153 from Convey-Compliance/pull-thread-safe-_get_host_port

Made _get_host_port thread safe
aggregation examples from Charlie Page
doc type fix for Reading BSON objects - CDRIVER-237
Merge branch 'master-mongo-c-driver-master'

Conflicts:
	src/mongo.c
problem with the merge