Abort the startup if we encounter a assembly scanning error

Since we now detect and don't even try to load non .net asm we can now blow up and stop the endpoint from starting.

We should make sure we create a good exception message telling the user:

* The assembly that failed
* The inner loader ex
* Tell them how to asm redirect
* Give them the syntax for the redirect (since we know the versions)

We also need a option to opt in to the old behaviour just to be safe. 

This also needs to work for the host (since the host passes the list of asms)