Patch for some bugs related to child process management.

Build will now properly end with an error code when a child mvn process fails at life.
Start will now get the pid of the java process rather than the subshell its launched from. 
Daemon mode will now fully exec the java process rather than try and propagate signals to it.
Status & Stop have a little more handling around 'failures' to parse the pid file. 
Stop will block and wait for its child to come down before exits... fewer surprises that way. 
Stop will kill by pid not process group.