[SashaMIT]

ReverseFileDiff swaps the index hashes and the diff --git paths. A GIT binary patch still keeps its two encoded sections in the original order.

git apply uses the first section as the forward result and the second as the reverse result. git diff -R --binary writes them in the opposite order. With only the hashes swapped, git apply --check reports creates incorrect result and the file is left unchanged.

The two sections are now swapped. A literal patch and a delta patch both reverse. On the reported bin.dat patch, git apply of the reversed diff turns 00 01 02 03 back into 00 01.

go test -count=1 ./diff/ passed. Before the swap, TestReverseFileDiffGitBinarySemantics still had literal 4 ahead of literal 2.

Fixes #98