All projects now target .NET 4 Client Profile.

When my company was evaluating CefSharp, the ability to target the .NET 4 Client Profile was a big factor, because it has a much larger install base amongst our business customers.  And they're the type that has to call IT for anything, and IT won't be happy about installing new framework versions.

I only had to change the target of all projects in the solution, so there were no actual dependencies on the full framework (i.e. System.Web and System.Design) - I guess someone already worried about this in the past, but didn't end up changing the targets?