Btest

* Adding btest-progress to setup.py. (Robin Sommer)

* Fix a failing test on FreeBSD. (Daniel Thayer)

* Fix a bug in btest-progress when using the "-q" option. (Daniel
Thayer)

* Fix some trivial errors in documentation and Makefile. (Daniel
Thayer)

* Add 'upload' Makefile target to upload to PyPi. (Jon Siwek)

* Fine-tuning diagnostic output. It needlessly stripped leading
whitespace. (Robin Sommer)

* Extending --groups to allow running everything *except* a set of
groups. (Robin Sommer)

* Fix portability issue with use of mktemp. (Daniel Thayer)

* Updates for Python 3. (Fabian Affolter)

* Improved test of TEST_DIFF_FILE_MAX_LINES. (Daniel Thayer)

* Added ability for a user to override the default number of lines
to show for diffs by setting the environment variable
TEST_DIFF_FILE_MAX_LINES. Reduced the default to 100. (Daniel
Thayer)

* When no baseline exists, changed btest-diff to always just show
the entire file. (Daniel Thayer)