r=nathan, komaln

Description:
track_stats runs command given and does one of the following:
        1. Writes its pid to /proc/fs/lustre/llite/.../stats_track_pid
 to collects stats for that process.
        2. Writes its ppid to /proc/fs/lustre/llite/.../stats_track_ppid
 to collect stats of that process and all its children
        3. Sets gid of process to some random gid (444) and also
 writes that to/proc/fs/lustre/llite/.../stats_track_gid to collect stats
of all processes in that group

 It also uses llstat to generate output with interval of 1 second and duration
 of run of command for plot-llstat to generate a graph