Added some cosmetic changes...

TODO:
1) 'Verify' -> we need to figure out how DES does this.
2) Format: BASE64 | ASCII -> ASCII is trivial, what if input is in
BASE64? or output is the cypher of some BASE64 input?
3) may be is worth to add some error msg in case config file couldn't be
found
4) :) -> we're almost there... KOL HAKABOD!!!

CHANGES:
1) Changed usage msg to reflect the correct usage options.
2) Added default case for dealing in case wrong operation parameters
were provided in the config file.
3) Added skeleton switch-case to deal with 'format' option.