ENH: Add new GetTypes() and GetTypesAsList() methods to the template class

This allows to know what types are wrapped for a class. This is useful because you don't
have to go and look in the .wrap file, and we currently don't build documentation for the wrappings.
The GetTypesAsList() is a more general method which could prove useful if somebody needs the raw sorted list.

This method could be extended to display more details and informations, like the list of available methods in the class.

I also removed unused sys imports and the unused has_key method.

Usage example:

>>> import itk
>>> itk.Image.GetTypes()
<itkTemplate itk::Image>
Options:
  [<itkCType double>, 2]
  [<itkCType double>, 3]
  [<itkCType float>, 2]
  [<itkCType float>, 3]
  [<itkCType signed short>, 2]
  [<itkCType signed short>, 3]
  [<itkCType unsigned char>, 2]
  [<itkCType unsigned char>, 3]
  [<itkCType unsigned long>, 2]
  [<itkCType unsigned long>, 3]
  [<class 'itkCovariantVectorPython.itkCovariantVectorF2'>, 2]
  [<class 'itkCovariantVectorPython.itkCovariantVectorF3'>, 3]
  [<class 'itkFixedArrayPython.itkFixedArrayF2'>, 2]
  [<class 'itkFixedArrayPython.itkFixedArrayF3'>, 3]
  [<class 'itkOffsetPython.itkOffset2'>, 2]
  [<class 'itkOffsetPython.itkOffset3'>, 3]
  [<class 'itkRGBAPixelPython.itkRGBAPixelUC'>, 2]
  [<class 'itkRGBAPixelPython.itkRGBAPixelUC'>, 3]
  [<class 'itkRGBPixelPython.itkRGBPixelUC'>, 2]
  [<class 'itkRGBPixelPython.itkRGBPixelUC'>, 3]
  [<class 'itkSparseFieldFourthOrderLevelSetImageFilterPython.itkNormalBandNodeIF2'>, 2]
  [<class 'itkSparseFieldFourthOrderLevelSetImageFilterPython.itkNormalBandNodeIF3'>, 3]
  [<class 'itkSymmetricSecondRankTensorPython.itkSymmetricSecondRankTensorD2'>, 2]
  [<class 'itkSymmetricSecondRankTensorPython.itkSymmetricSecondRankTensorD3'>, 3]
  [<class 'itkVectorPython.itkVectorD2'>, 2]
  [<class 'itkVectorPython.itkVectorD2'>, 3]
  [<class 'itkVectorPython.itkVectorD3'>, 3]
  [<class 'itkVectorPython.itkVectorD3'>, 4]
  [<class 'itkVectorPython.itkVectorF2'>, 2]
  [<class 'itkVectorPython.itkVectorF3'>, 3]
  [<class 'vcl_complexPython.vcl_complexF'>, 2]
  [<class 'vcl_complexPython.vcl_complexF'>, 3]

Change-Id: I4322c588bbc605dd802ddc7215a56f6777d31c8b
Merge topic 'InfoWrap'

75469ffe ENH: Add new GetTypes() and GetTypesAsList() methods to the template class