phabricator: fix a phabsend crash when processing a renamed binary
This was a trivial fix, and some more tests are added to cover binary files.
Since the old filecontext is passed in, the old name is still available. But I
noticed some weirdness around what it marked as binary and not, and what is
viewable in Phabricator. Those things have been flagged, and will probably take
some digging.
Differential Revision: https://phab.mercurial-scm.org/D8133
$ hg init
$ echo a > a
$ hg ci -Am t
adding a
$ hg mv a b
$ hg ci -Am t1
$ hg debugrename b
b renamed from a:b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3
$ hg mv b a
$ hg ci -Am t2
$ hg debugrename a
a renamed from b:37d9b5d994eab34eda9c16b195ace52c7b129980
$ hg debugrename --rev 1 b
b renamed from a:b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3