Removed long-ago-deprected file spynumtut.py.
Removed all references to numpy.oldnumeric.
Updated version to 0.16.dev-1.
[Issue #11] ENVI 8-bit data type is unsigned.

- Correctly maps ENVI data type "1" to 8-bit signed integer
- Raises an exception when attempting to save an image data type not
  supported by the ENVI format (e.g., 8-bit signed integer).
- Adds function get_supported_dtypes to return list of supported
  image data type names.
Merge branch 'oldnumeric' [fixes #13]
Merge branch 'issue-11' [closes #11]
Add support for writing ENVI Classification files.

* Add envi.save_classification().
* Move most of envi.save_image() to other functions so code can be shared
  between the save_ functions.
* Update ENVI's company name.