Add testsuite configuration in phpunit.xml.

This allows phpunit to be called without specifying the testsuite
location.
Enable strict code coverage.
Access PHPUnit as a library for gathering report.

See dominionenterprises/util-php#32 and dominionenterprises/util-php#33.
Merge pull request #1 from nubs/master

Access PHPUnit as a library for gathering report.