Fix typo in upgrade docs

Removed extra closing parenthesis
geo_within docs - fix broken code samples

No such thing as "geo_with"
Merge pull request #553 from davidwilemski/patch-2

Fix typo in upgrade docs
Merge pull request #554 from yprez/patch-1

geo_within docs - fix broken code samples
Stop ensure_indexes running on a secondaries (#555)
Merge branch 'master' of github.com:MongoEngine/mongoengine
Fixed possible issue not catching duplicate key errors
Fix circular import issue with django auth (#531) (#545)
Calling reload on deleted / nonexistant documents raises DoesNotExist (#538)
0.8.7