Bug 1021756 - Add function to request information about a process. r=wlach

The function processInfo returns a tuple with the pid, path and owner of
the process. This is useful if we want to determine if a process is owned
by root or not.
Bug 1021756 - Allow to run adbd as root. r=wlach

This allows a device that starts adbd as non-root to restart adbd
every time that is needed to ensure the ability of running
privileged tasks on the device.