added documentation for safe:false and versioning interaction
fixes #1520; versioning is disabled for unsafe writes

Automatically disables versioning for unsafe writes (ie. { safe: false } at
the schema level)
updated; mquery to 0.3.1
fixes #1280; properly excludes subdocument fields

Before, you would have to specify the full subdocument path and all
properties to exclude it. Can now just specify the top level
refactor a bit
Merge pull request #1626 from 10gen-interns/versioning-fix

Versioning fix
fixed; handle another versioning edge case

Follow up for #1520
fixes #1445; setters not firing on null values

added tests as well
ocd
explicit test for #1445
update history
updated; driver to 1.3.19
tests; fix 2dsphere test on MongoDB 2.4
release 3.7.3
now working on 3.7.4