Add the memtrack utility.

This utility attempts to track the PSS usage of all of the
processes in the system. It will keep track of the min/max/avg/last
PSS for every process it has ever seen and dump that information when
the program is terminated or when a USR1 or TSTP signal is sent to
the process.

Change-Id: Id9364d5121b70f80b8335c379a241bee2fbdb019
3 files changed