- Add phpdoc configuration file.

This allows us to make more detailed request on what to generate documentation for

- Split phpunit testsuite into smaller pieces.

This is useful if you don't want to run all unit tests, but still everything in one package.
Invocation syntax for this would be like:

phpunit -c tests/phpunit.xml --testsuite "Gravity"

ran ant targets and phpunit with all different testsuites