InlineEdit: Don't offer edit icon on binary files

Currently there is no way to retrieve patch type info in side by side
screen.  Extend GET changes/<id>/revisions/<rev>/files/<path>/diff
to return binary flag. Suppress change edit icon on patch set select
panel when binary file is opened.

Bug: Issue 3162
Change-Id: I92daf8fde462a0c9977821a60fb19538e4bfae45
9 files changed