This patch updates msvs/msvc settings for all Express (for Desktop) versions of Visual Studio from 2008-2013. I've verified these settings on my Win7 box against my nohtyP project build. (Unfortunately I do not have the commercial versions of these tools, nor do I have any older versions of MSVS.)
I'm also including a few fixes to the test system that prevented me from running the tests.
I've confirmed that default_dirname was flat-out incorrect for Express versions from 2008 onwards. I decided to remove it instead of fixing it as I could find nowhere inside of SCons that uses it. But because I couldn't confirm it was incorrect on earlier versions, I decided to keep it, on the thinking that perhaps there are builds out there that reference it directly.
With sdk_version, I again verified on Express 2008+. The new versions are, with one exception, all greater than they were previously, so I would expect these new values are "better". The "one exception" is both versions of 2008, which drop from 6.1 to 6.0A; this is correct as-per Wikipedia, and I've verified it works on Express.