Major: Default port is 3306 instead of automatic (auto. now explicit)
Major: Clearer error message (incl. output) in case of "already exited"
Major: Auto. Socket from temp. dir instead baseDir
Major: MariaDB4jSpringService setters are defaults (incl. tests)
Medium: detectFreePort() protected method; public setPort(0) is clearer
Medium: Fixed corner case of setSocket() with relative path
Minor: JavaDoc for MariaDB4jSpringService
Minor: moved tests to sub-packages
Minor: TODO cleaned-up a bit

Signed-off-by: Michael Vorburger <mike@vorburger.ch>