streamlining and more conversions.

Added the ability ton convert freely between all four bases (binary,
octal, decimal, and hexadecimal).  Streamlined the functions to work
more smoothly with the new added functionality.  Removed the second get
num from user method, and incorporated its functionality into
GetNumToConvert(char foo).  Now store and pass all number values as
strings, for simplicity.  Only convert from string to uint when
necessary.