[altq 739] Accounting mode

[Long Le <le@cs.unc.edu>]

Hello,

I'm trying to adapt some code that was added ALTQ 2.2 fifoq-tools and
red-tools (the code does some logging of information for our own
purpose)
to ALTQ 3.0 and found in the CHANGES note that the accounting mode has
been removed.

Although I don't think that our code relies on this mode, I want
to make sure that the change does not have any side-effect.

What was the accounting mode for and why has it been removed?

Thanks,
-- long