Move builtin class sources(*.jet) under IDEA module (should be removed completely later)
Change marker filename which is used to find those sources via getResource
Add KotlinInfo annotation, serialize classes to bytecode
Don't serialize non-serializable types

If there's a private property in a class which has a type of some local
class/object, write its type as jet.Any (otherwise there's no obvious way to
construct a FQ name of such type)
Don't load KotlinInfo annotation in resolve.java
Fix property setters serialization, hasGetter->hasSetter
Adapt to protobuf style guide

Identifiers consisting of multiple words should be separated by an underscore,
repeated field names should be singular
Serialize property setter parameter names
Minor, reuse existing namer for built-ins
KotlinInfo now has only one parameter data

Name table is now also stored in data, before the serialized class.
ClassData is now public, since it's used in plenty of places as a holder of
deserialized protobuf classes.