[PATCH V3] bundle2: move 'seek' and 'tell' methods off the unpackermixin class

[Ryan McElroy]

On 4/11/17 8:48 PM, Pierre-Yves David wrote:
> # HG changeset patch
> # User Pierre-Yves David <pierre-yves.david at ens-lyon.org>
> # Date 1491757747 -7200
> #      Sun Apr 09 19:09:07 2017 +0200
> # Node ID 655fb7e6bb117d896ab43adbf8d581e3780d82cf
> # Parent  cd7aaf344d83988f77d0bcb983b9ee1cf01b704d
> # EXP-Topic bundle2.doc
> bundle2: move 'seek' and 'tell' methods off the unpackermixin class
>
> These methods are unrelated to unpacking. They are used internally by the
> 'unbundlepart' class only. So me move them there as private methods.
>
> In the same go, we clarify their internal role in the their docstring.
>
>

This version has all of the improvements I hoped for. I've marked as 
pre-reviewed in patchwork.