Modify the regex handling so that we can match fortunes in rot13'ed
databases (rot13 the pattern and maintain a second compiled pattern)
and rot13 the rot13'ed fortune before output.
Move the rot13 code to a function since it's now used in three places
instead of just one.
Initialize posfile in one place since it appears to get used without
being initialized when using debugging.
Make a *slight* improvement to the random seeding by squaring the pid
and then xor'ing against the current time, since just xor'ing the time
with the pid will not change if they both advance by one from "odd" to
"even".