Make path, channel and unit handling smarter.

This fixes issues with reports that aren't in the same directory as, with running and from other
directories, and with Iperf automatically scaling units.

It doesn't do some of the other things I've talked about, like
converting Iperf units to more sensible ones, or finding channel
boundaries correctly on Linux VHT channels. I'm thinking that both are
clever enough they're best done in a later FiberCL.

Change-Id: Ia8dcee3a04c26e53475c686203ffbc325405d611
3 files changed