[mythtv] Proper way to create a patch

[Jason Donahue]

Hello,
I have done some coding for mythweb's music page to extend it's
functionality, and would like to submit a patch. Problem is, I'm not sure
how to do it right/conform to what is wanted.

I figure I should be doing 'diff -u', but my changes affect multiple
files, some in subdirectories, and creates a couple of files as well. So,
is there a nice command to create one big diff file on the directory?