Byte Buddy 0.6

• Renamed the Instrumentation interface to Implementation to avoid naming conflicts with Java types.
• Renamed the Field annotation to FieldProxy to avoid naming conflicts with Java types.
• Refactored package structure to make the implementation more readable.
• Added possibility to define annotation default values.
• Avoid creation of an auxiliary placeholder type for method rebasements if it is not required.
• Avoid rebasing of methods if they are not instrumented.
• Reimplemented TypeWriter, MethodRegistry and other supporting infrastructure to make the code simpler.
• Refactored testing that is related to the previous infrastructure.