[MiroDev] cleaning up the code base

[will]

Over the last few weeks, I've been spending my "my brain hurts and I 
can't think straight" time removing dead code, fixing code based on 
pylint output, and otherwise tidying up the code base.  The motivations 
are these:

1. dead code is bad code

2. pylint is showing errors that are bugs waiting to happen--not a lot, 
but they do exist

3. fixing code convention issues will make it easier later on to have a 
consistent API for plugins


I'm taking the opportunity to be a bit more aggressive than I would 
normally be with this because we're re-implementing a lot of stuff and 
we're going to have to do a lot of testing, so it's better to take 
advantage of that and introduce breakage now rather than later in the 
development cycle.

The reason I mention this now is so that everyone is aware that this is 
going on and that it's introducing a lot of checkins and code flux.  I'm 
trying to be really careful and methodical with the changes I'm making, 
but...  I'm probably making mistakes that you all will bump into.  I'm 
also trying to do it during nights and weekends so as not to affect 
developer flow...  though since we're all using git over svn, I'm not 
sure how much difference that really makes.

Feel free to peer-review the checkins.  I'm trying to keep checkin 
comments informative and make small changes per checkin to make this easier.

I also welcome any help doing this work.  If you don't have svn checkin 
access, feel free to send me cleanup diffs against current trunk.

/will