Clean up packaging and Makefile, including docs in packaging.
Fix 'make test' and 'make doc' in conda environments.

These commands rely on distutils setup.py commands, which are not installed in the conda
versions of the nose and sphinx packages. Install them in setup.py just to make sure.
Also make Makefile more friendly to copying to other projects by specifying package name
as a variable.
Ignore generated sphinx doc files in git.