Startup dir is now /c/dev

I went through the Windows installfest last night. When performing the Console2 installation, I found the directories mentioned to be inconsistent.

It looks like some previous version of the instructions used `c:\Sites`. Now they use `c:\dev`, but there were still a couple of references to Sites. I've updated those references.

In the January workshop, I noticed several students had their Rails project *under* the Console2 directory. This happened because the default startup dir for Console2 is... the Console2 directory. I've added instructions to set the Startup dir to c:\dev.