KT-3267 Put binary format version into the generated class files
#KT-3267 Fixed
Warnings fixed, annotations added
KT-3268 Check binary format version in the compiler
Kotlin classes always have a signature
Outer's superclass' method is now inaccessible from nested

Also the diagnostic error message reported the wrong nested class name: it
should be the nested class in the hierarchy which is static, not the class of
the scope where we're checking the accessibility
KT-3263 Add a quick fix to make a class inner