Guard against reading a possible undefined in server::canCheckoutWriter
Issues #993 Some test have duplicated names
Fixed read preference inheritance as well as aggregate helper, added tests Issue #999 and #995
Changed NEAREST to use round robin instead of Random pick of eligable servers so more predictable picking of server Issue #998
Merge pull request #994 from kawanet/work

Issues #993 Some test have duplicated names
Fixed test names
Merge pull request #992 from willyaranda/master

Guard against accesing a property when isMasterDoc is undefined
Introducint read and write preferences to gridstore
Ensure db readpreference is propregated only if replicaset readPreference is not set, #998
Fixed docs for poolSize and replset as well as fixed typo bug, Issue #1000
Execute stored queries on master server switch.

Execute all stored commands, both queries and writes (currently on stored writes are executed), when the master server is switched.
Updated package and history
Fixed npm ignore