Fix proposal for issue #1164

[orphaner]

Sometimes Kong can't start after stoping a docker container without invoking
the kong stop command. The error message is "[ERR] dnsmasq is already running".
Since the container has been stopped, all processes in that container has been
stopped as well.

My idea is that the BaseService:is_running() method
https://github.com/Mashape/kong/blob/0.8.3/kong/cli/services/base_service.lua#L56
may not work well. It runs 'kill -0' on the pid contained in the
/usr/local/kong/*pid files which is a good idea to check if a pid exists
as a process but it does not check that the process is the expected
process. In other words, the pid contained in the dnsmasq.pid file can match
an existing process which is a totally different process than a dnsmasq one.

Furthermore, in a docker container these pids belongs to the previous launch
of the container.
The fix I suggest is to remove all the pid files contained in
/usr/local/kong before running the kong start command.

[subnetmarco]

Fixed in 0.11 (dnsmasq removed in 0.10.x)