diff: add --binary option for git mode diffs This patch adds --binary option to `hg diff` and `hg export` to allow more control about when binary diffs are displayed in Git mode as well as some tests to verify it behaves correctly (issue5510).

patch: make diff in git mode respect --text option (issue5510) This changeset makes patch respect -a/--text option in --git mode by aligning its behaviour with git itself.