Cannot colocate uaa & login (and probably servicesmgmt job)

```
$ sudo grep monit /var/vcap/bosh/log/current
...
2013-06-12_00:16:51.98024 /var/vcap/monit/job/0000_core_noprops.login.monitrc:1: Error: service name conflict, vcap_registrar already defined '/var/vcap/sys/run/vcap_registrar/vcap_registrar.pid'
```

It turns out that 3 jobs all create the same pid file:

```
$ grep "vcap_registrar/vcap_registrar.pid" jobs/*/monit
jobs/login/monit:  with pidfile /var/vcap/sys/run/vcap_registrar/vcap_registrar.pid
jobs/servicesmgmt/monit:  with pidfile /var/vcap/sys/run/vcap_registrar/vcap_registrar.pid
jobs/uaa/monit:  with pidfile /var/vcap/sys/run/vcap_registrar/vcap_registrar.pid
```

Proposed solution: put the pid file in the `/var/vcap/sys/run/JOB` folder. This is what we do/did for nginx.