a4/a4 — pull request #192 by pwaller (2012-11-05 18:18:44+00:00)
Title: Rename some member variables to begin with _, and some privatization

Whilst trying to reason about some of the code within the driver
I had quite a bit of difficulty finding where some of the variables
where defined due to their naming, e.g. `in`, which if you grep for it
gives you lots of hits which are not variables.

This patch renames most of the private variable names in the driver
to begin with _ so that when reading the code you can clearly see
which pieces belong to the `*this`.