This change adds support to the SVNPatcher for applying binary files

as part of changes. Things have been reorganized a little bit in order

to make it easier to deal with both empty files and binary files, which

appear similarly in the diff.
Additionally, several of our tests had index lines that did not start

with a /, which was inconsistent with real-world data. I've fixed

these up to match.

Ran unit tests.
Used rbt patch with a bunch of changes that did various file

  operations on binary files.