Otherwise some tools break (e.g. CheckMethodAdapter in ASM, used in generic
signature writer) because they expect class names to be Java identifiers.
Some tests fixed, some will be fixed in future commits
Package fragment classes now are named "*Package-<filename>-<hash>" instead of
"*Package$src$<filename>$<hash>". This will help to avoid erroneous code in
intellij FileManager, which assumes that classes with dollars are always inner
classes of some other class (see AnnotationDescriptorDeserializer)
