Adding solution files for building with libraries installed by the Windows installer

We recently got serious about distributing libraries on the Windows platform via an installer and someone asked about building your example with the installed libraries, which needed a little tweaking. I split your set of solution files into two: one for libraries built from source using the MSVC++ solution files included in the Cbc source distribution and one for libraries installed with the installer.

I'm still learning git so please forgive any transgressions :). I forked your project into the newly founded COIN-OR area on github. I'm not sure if that's the way to go or if I should have just asked you if you want to move your project under COIN-OR. I'm still in the process of learning about github enough to understand how to build up the COIN-OR organization and what the implications are of just forking COIN-related projects versus transferring them in.