0.18 2009-11-25
* Connections now support connection pooling. See http://api.mongodb.org/ruby/0.18/classes/Mongo/Connection.html#M000158
* Deprecated :auto_reconnect option on connection; if the driver fails to
  connect, it will automatically try to reconnect on the subsequent operation. 
  See http://www.mongodb.org/display/DOCS/Replica+Pairs+in+Ruby
* Added Collection#map_reduce helper (Christos Trochalakis)
* Deprecated DB#db_command in favor of DB#command.
* Removed deprecated old sort options, :offset, and Connection#clear.
* Lots of internal code restructuring for better maintainability.

0.17.1 2009-11-17
* Index ordering fix
* Notice to install mongo_ext

0.17 2009-11-16
* Performance improvements
  * large document inserts twice as fast as 0.16
  * queries 18% faster than 0.16 on average
  * see benchmark comparison: http://gist.github.com/236062
* Support for multi-update for Mongo >= 1.1.3 (See Collection#update)
* Collection#distinct
* Connection#copy_database (voodootikigod)
* C optimizations for ByteBuffer#to_s and ObjectID#generate (seancribbs)
* Continue code restructuring for performance and simplicity.