add docs about callbacks
Merge pull request #1547 from nikmartin/3.6.x

add docs about callbacks
Merge branch '3.6.x' of github.com:LearnBoost/mongoose into 3.6.x
Fix wrong isSelected() behavior.

When fetching a document with some fields selected, isSelected() always
returns true with any fields starting with that selected-on-fetching fields'
name but which is not really selected on fetching.

 #1521
Fix missing return statement in SchemaArray#$geoIntersects()
Add tests for $geointersects
fixed issue with findOneAndUpdate not returning null on upserts

if new=false, upserts were not appropriately returning null. fixes #1533
docs; note about toObject behavior during save()
bump driver to 1.3.11
release 3.6.14
Merge branch '3.6.x' into gh-pages
website; 3.6.14