extended functionality - focuses around es6

Changes

• Cleanup unused note
• fix readme links
• add initial interface support
• es6 return jsdoc
• python return docstring
• ignore header ... endheader
• improve error handling
• better way to pick right parser
• parse abstract method
• parse default value for method parameters
  • es6 jsdoc support
• allow * as function name prefix (es6 yield function)
• parser: allow quotes for default value
• es6: render string default values properly
• es6: List<Value> as an method return value is rendered now properly (fixes #9)
• sample puml updates