change build system to GNU autotools?

Related to #169 (closed), I am concerned that our hand-maintained makefiles are becoming unwieldy. I looked at some options (CMake, Scons, GNU autotools), and it seemed the most viable option was GNU autotools.

The first step is to determine feasibility, i.e.:

• How hard is converting to GNU autotools?
• What, specifically, are the steps needed to convert? (e.g., how do we deal with .so files in the test suite?)
• What improvements can be gained? (e.g., patching Python scripts against Python 2 or 3 at build time)