Updated .gitignore
Fixed a test that failed with PyMongo 2.0.
Worked around a garbage collection issue with PyPy in MongoDBManager.map_reduce(...).
Made the tox file actually useful.
Don't drop test database but delete all collections (keeps users)
Made the test settings non-default-db-configuration friendly
Add .tox to gitignore
Made the tests work with MongoDB 2.0.

Using w=<n> without a functional replica set setup throws an error in
MongoDB 2.0 whereas in 1.8 it didn't.
GridFSField: Multiple save() calls should not create multiple files
#65 Added support for versioning + delete using the first file ObjectId as filename of the nex versions
 Lets keep the issue open waiting for usecases.
Should we add support for other versions retrieval ?
old comment removed. Collections support implemented
Refactored GridFSField tests
Make the GridFSField tests pass
tox.ini fixes
Introduced a new 'MongoMeta.indexes' for MongoDB-specific indices.

'MongoMeta.{sparse_indexes,descending_index,index_together}' were
merged into a new 'indexes' attribute and are deprecated as of now.

Closes #68. Credit goes to Ellie Frost for bringing up the idea and
initial work on a patch.
Reduced the amount of code in docs/conf.py
Added a 'docs' environment to tox.ini
README cleanup
setup.py cleanup
Fixed a few typos in the docs