fixed #1412; Subdocuments use their own transform

Made it such that subdocuments will use their own transform function
instead of their parent's when `toObject()` is called
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)
docs; openNewDb
db.openNewDb -> db.useDb
small refactor of useDb
changed the names of a couple benchmarks
Merge branch 'master' of github.com:LearnBoost/mongoose
Fixes gh-1606, dealing with ref docs on creation

Passing values at creation time and setting afterward now consistent
with each other. fixes #1606
added tests for gh-1606
refactor
update History
release 3.7.1
now working on 3.7.2
All benchmarks drop db when finished now

Before, several of them just "deleted" everything in the db. This way is
faster, simpler to code, and more robust.
website; update guide
tests; handle different result order
tests; handle differing result order
tests; handle result order
tests; handle result orders better