Add no-consecutive-numbers filter
Remove potential NULL dereference (caught by clang analyzer)
Add base-sequence variable
Add max-run-time variable to stop after a specified number of seconds.

Note that the code only actually checks every 1000 iterations, so
for heavily computational searches, it could run over time by a
few minutes. So leave some slop.
Alphabetize the 'Variables' section of the README

It was almost correct..