Install notes
1. Unzip the zip-file.
2. Read the "Recent Changes" and the "Known Problems" pages 
   as far as informative for you (See http://www.37steps.com/prtools)
3. Copy or move the prtools folder to a Matlab working directory.
4. Store the other files somewhere for future reference.
5. Start Matlab
6. Add the prtools folder to your path, either by the "Set Path" 
   entry in the "File" menu or by the addpath command.
7. Run prex_plotc
   If you see a scatterplot with some classifiers, everything is fine.
   If you just see a listing and warnings, but no scatterplot, graphics
   are not enabled or tunneled.
   If you see errors, something is wrong:
   - "Undefined function or variable 'prex_plotc'", means that prtools 
     is not in your path.
   - other messages may be caused by a collision of toolboxes, 
     See "Known Problems"