Test conflict between member mapping and constructor in destination clas...

I've found that if a destination class has a non-default constructor, it'll take precedence over any member mapping in said class. This leads to mysterious errors, if you depend on member mapping in order to be able to translate source properties, which can be really hard to pin down. It took me several hours of debugging AutoMapper to figure out what was going on.

I'm not sure how to fix the issue so all this branch does is add a test to detect it.