implemented AJP connector setup

Hi Benjamin,

I've implemented the possibility to add and configure an AJP connector. What do you think? I've tested it using the tomcatRun task and the configured default values (port 8009, org.apache.coyote.ajp.AjpProtocol). Switching to the org.apache.coyote.ajp.AjpAprProtocol leads to an exception (missing ARP/native library). I'm not sure how to add this library to the gradle process.

Best, 

Moritz