fatrace (file access trace)

fatrace reports file access events from all running processes.
Its main purpose is to find processes which keep waking up the disk
unnecessarily and thus prevent some power saving.

Included is a python3 script called "power-usage-report", which
uses fatrace and powertop to build a textual report from one minute
of measuring power usage and file accesses. This does not take any
arguments or require any interactivity, so it's very simple to use and
serves as a starting point for bug reports or optimizing a particular
installation.

fatrace has self-test scripts that can be run during the build. These
are disabled by default. If you want to run the tests, export
RUNTESTS=yes in the environment.
