Import autogen script from pip-db

See: https://github.com/ChrisCummins/pip-db
autogen: Fix AC_PREREQ regexp for bracketed values
configure: Bump version number to 0.0.7
configure: Use a structured, literate script style

Based off of pip-db's configure script.
make: Add conditional logic for --enable-tests
make: Add conditional logic for --enable-man-pages
Update git ignore with new file locations