:muscle: implement `$.Func` that is the brief version of `$.Function`
:muscle: change how to build a class, use `klass.builder`

  - rename klass/klass.js -> klass/define.js
  - add file klass/builder.js
  - builder.addClassMethod
  - builder.addMethod
  - builder.addProperty
  - builder.subclassResponsibility
  - builder.doesNotUnderstand
  - builder.shouldNotImplement
  - builder.notYetImplemented
  - builder.notSupported
  - fix SCRoutine constructor
  - reduce klass.utils, instead use lang.$ and klass.builder
  - fix tests
  - fix `grunt impl`
:lipstick: fix to define properties of SCInterpreter
:lipstick: fix to define methods of SCInteger/SCFloat