Fixed exception handling

There were errors in the exception handlers that were triggered by the use of dynamic objects, like commonly present in ASP.NET MVC applications. Infinitely nested first-chance exception handlers lead to a StackOverflowException that crashes the web server process. Also, some information like module or declaring type are not available for dynamic objects. RuntimeBinderExceptions are no longer logged as first-chance exception since they're very common and not significant.

Also fixed the build script to find the signtool if Visual Studio 2013 is installed. (Untested with VS 2012.)