Support for .NET 4.0

[matthewadams]

winsw.exe targets .NET 2.0. Recent Windows distros (like 8.1) don't include .NET 3.5 or earlier. This allows the current winsw.exe to run against both .NET 2.0 & 4.0. See:

• https://github.com/kohsuke/winsw/issues/103
• https://github.com/kohsuke/winsw#net-runtime-40
• http://www.davidmoore.info/blog/2010/12/17/running-net-2-runtime-applications-under-the-net-4-runtime/

This change adds a .exe.config file to the service executable, allowing it to run unchanged against .NET 4.0.

[matthewadams]

I didn't check other pull requests before doing this work. https://github.com/coreybutler/node-windows/pull/83 looks like a bit better implementation (it's been quite a while since I developed on Windows). You might consider my winsw.exe.config file, rather than hard-coding the contents like @gm112 did; it has a bit more content that might help the user unfamiliar with the .NET <configuration> element & its children.

[coreybutler]

I'm finally closing this (.NET 4+ support is now in via another PR). I'm only 2yrs late in thanking you (my apologies).