Add missing libcef_dll_wrapper.lib in CEF/Win32/Debug/VS2012

This fixes #272.

I had to change .gitignore a bit.

I compiled libcef_dll_wrapper.lib with VS2012 as @jornh suggested using the following code
https://github.com/cefsharp/cef-binary/commit/fe11112e8244868ede15c7c9dc727e8d505fadc3.