JHV 2.0: Optional features for AGU

- OpenGL Filter functionality:
- invert color table
- apply gamma correction: calculate gamma-corrected color table and pass it along to the pixel shader
- apply sharpening filter (convolution filter)

- passing command-line arguments: JHV 2.0 needs to at least support the options provided in version 1.0
   (see http://achilles.nascom.nasa.gov/~alen/dev/interface.html). These are useful when launching jhv using a jnlp
   file. A basic command line processor class is provided in version 1.0 which can be used in version 2.0. Another option would be
   to use one of the several command line processing libraries which are used in java community and can be found online.