[PATCH 1 of 8] bdiff: add _version to help detect breaking binary changes

[Yuya Nishihara]

On Tue, 2 May 2017 18:33:50 -0700, Jun Wu wrote:
> The problem we faced for issue4042 fix is to maintain compatibility in both
> directions without copy-paste.
> 
> The "_duralmodule" approach is while smart, does not really solve the above
> problem. i.e. copy-paste is still needed.

No. We can just rename fix_newline() to fixnewline2(). New code has
pure.diffhelpers.fixnewline2() as a fallback, and old one does
pure.diffhelpers.fix_newline(). That's how we solved API changes historically.