PyPI "distribution name" changed, 1.11.0a2 tagged

[Brian Warner]

Today we finally closed ticket #2011, which changes the PyPI
"distribution name" from "allmydata-tahoe" to "tahoe-lafs". This is the
first step in the long-overdue "allmydata-ectomy" that mostly lives in
ticket #1950.

I wanted to get this into 1.11 so the install instructions can be a
consistent "pip install tahoe-lafs". If we didn't make the change now,
the instructions would have been to install "allmydata-tahoe" and then
would change later.

If you have a git clone of the source tree, and update across this
change, you may need to do a "make distclean" to avoid a warning about
src/allmydata/_appname.py changing. You should also "pip uninstall
allmydata-tahoe" from your virtualenvs before re-installing tahoe. If
things remain weird, you may want to switch to a fresh git checkout, or
scrub the tree down to the bare floor (i.e. clobber everything but what
git knows is supposed to be present) with "git clean -ffdx".

This also changes the name of the tarball, from e.g.
"allmydata-tahoe-1.11.0a1.post16.tar.gz" to
"tahoe-lafs-1.11.0a2.post3.tar.gz".

To get the compute-version-from-git code to work, we had to push a new
git tag (with the new "tahoe-lafs-" prefix). So this is also an
announcement of the "tahoe-lafs-1.11.0a2" testing release. Due to the
way we managed this one, a2 is not a GPG-signed tag. But subsequent tags
(including the final tahoe-lafs-1.11.0" one) will be signed.

One note: we think we've fixed the problem in which a python3-based
"tox" cannot run tahoe's py2-only test suite (#2747). This affected many
debian/ubuntu users, for whom the OS-installed "tox" is based on py3.
You should be able to do "git clone; tox" now.

We think we're mostly done with code and packaging changes. The
remaining issues for the 1.11.0 release are docs: updating to match the
new world of pip/virtualenv/tox, and adding notes about dependencies.

cheers,
 -Brian