loadlist() will now return a dictionary of the word list when
successfully loaded and None on failure. The unnecessary main
script was removed and core.py took it's place. Wording was
further changed from "password" to "passphrase."
The number generator disproportionately favors digits 1-5 over 6. This
fixes it using random's randint() function and the SystemRandom class.
Function numgen() will now always return a list.
