1) Generalize menu.  Query the cipher class to find out what options
   are valid and display them inside of cipherdata.
2) Plan out how to use class quag as a generic quagmire base class
3) Add help documentation.  There should be a 'h'elp option at every
   prompt that will either list the appropriate responses or give a
   description of that cipher type and what can be done to it.
5) Fix key routines for:
    b) checker
    d) phillips
6) Add solve option for:
    a) nihilist transposition
7) Add Myszcowski cipher type and derive columnar transpositions and
   rail ciphers from it