Changed .lines to store metadata; Added repeated-line counter

* The lovebird.lines table now stores metadata for the printed line:
  the time it was printed and the number of consecutive repetitions of
  that line to occur.
* Consecutive duplicate lines now get a little repeat count marker
  instead of having the line print out multiple times.
Changed lovebird.allowhtml's default to false; updated README
Added support for up/down keys on input box to recall past inputs