Spectral Python 0.19

New Features

• Rendering functions accept an "ignore" keyword to indicate a bad data value
  that will be ignored when calculating color histogram stretches.

• Added iterator_ij to iterate over all pixel coordinates for a given
  image mask.

• Added expand_binary_mask_for_window to expand an image mask to include
  all pixels within a fixed size window around each masked pixel.

• Added support for bad band lists (bbl) in ENVI headers and suppress display
  of bad bands in spectral plots

• Added optional support for non-lowercase ENVI header parameter names (issue #63).

Changes

• principal_components also accepts a GaussianStats object, which can
  avoid the need to recompute image/class statistics.

• Added a SpyException base class for package-specific exceptions.

• Added "raw" to the list of checked ENVI image data file extensions.

Bug Fixes

• Fixed a bug that potentially produced incorrect results in map_class_ids
  (issue #53).

• Removed unecessary import that cause python3 compatibility error in
  aviris.open (issue #54).

• Removed has_key call breaking python3 compatibility (issue #56).