Update README.md file

The README.md needs to have adjusted the way how Conficius is created
and how AllowedReferenceRelatedFileExtensions should be set.
Fix detecting called type in ConficiusCaller.

Currently ConficiusCaller tries to get the DeclaringType of the member
which called him. He should use the ReflectedType instad of DeclaringType.
Fix allowed reference related file extensions in the main project.

The AllowedReferenceRelatedFileExtensions tag allows us to specify which
files (identified by extensions) should be copied into to output order. In
case when only .dll.config was specified the .pdb files was not copied and
it prevented us from debugging the referenced code.