OrderedDictCursor

Thanks for making this package, I have really found it helpful.

Here's a basic implementation of a cursor that returns an ordered dictionary matching the field names of the query, in order.

I have a test for it, which passes.

I wasn't sure what to do for py3k support, nor the best way to disable the functionality if the OrderedDict package (either from collections, for python >= 2.7, or in the OrderedDict.py equivalent recipe for python >= 2.4).

If you elect to include it, please let me know, I'd like to see how to handle both of those things in the future.