How to provide a patch?

[jlangley]

Hi,

I've done a bit of work that I'm using on a program where I have added  
Snappy compression support to the C++ DataFile class.  I also added a  
unit test to test the changes.

I would like to make this available to the Avro community, but I don't  
know how to do that.  Also - I'm not familiar with the CMake process  
for adding Snappy as a dependency, so that part would probably need to  
be redone.

Is this as easy as running some kind of patch script to create  
something from Subversion?

Thanks,
-J. Langley