Update Texi2html transformation. 
    
        - Change caution messages from red background to orange
          background. 
    
        - At present time, I don't fill confortable with red background as
          I am with orange background for warning, tips, caution and
          important messages. Blue looks ok for notes, but that red
          background ... mmm I don't think so.
    
        - Other colors like, gray, green, and violet remain still unused.