Feature: Submission instrumentation

[Hapstyx]

Adds a bytecode transformer which provides the following features:

• Mapping submission classes and their members to solution classes for better testability
  • Can be forced with the @ForceSignature annotation
• Invocation logging for methods and constructors
• Method substitution, i.e., dynamically run arbitrary code instead of submission code
• Access to original class, field and method / constructor headers

Roadmap:

• Add more configuration options (similarity matching threshold, etc.)
• Constructor substitution
• Replace specific method calls project-wide (e.g., calls to methods in java.util.Random)
• Add ClassLoader for regular JUnit runs