Support building wheels (PEP-427)

With that, building and uploading wheels to PyPI is only one "python
setup.py bdist_wheel" away.

Change-Id: Idfc291f496a81498df6408f189854f49eca496d3
Bump the development status classifier.

Change-Id: Ib64c45080ad256fd0019072deef19fb76516486c
Merge "Bump the development status classifier."
Merge "Support building wheels (PEP-427)"