On "start" command check for Yate process by PID file, warn if already running.
Added "force-start" for those who want to override any checks.


git-svn-id: http://yate.null.ro/svn/yate/trunk@5820 acf43c95-373e-0410-b603-e72c3f656dc1
Merge branch 'upstream' of github.com:vir/yate into deb
Updated debian package version to 5.2.1~svn5820