Added compile_to method that with single .compile() can produce multiple target files.

This is my take on issues/568.
What do you think?
Also, I think I'd prefer 'object_name', 'assembly_name', or 'object_filename', 'assembly_filename', etc. 'fn' again has a bit of an overloaded meaning. Also, at some point, I'd like to try to figure out a way to compile all of the variants of a generated Func into one object, which would make the 'fn' a bit misleading.