fixes to search strategy:
 slow functions are now kept for construction of further results (via the "force" mechanism in the updater)
 evaluation is extended to take account of the time to combine the constructor function with the operand functions (e.g. so the Marc's big num can time out gracefully)
  will yield the procedure #f in this case, which will propogate forward to new falses (i.e. if you try to square bignum)
Additionally:
  the "val" object doesn't just store the code and complexity and procedure; now it stores computation time and result as well
  dump-functions and dump-slow modified to account for this
  dump-functions now based on v-lv, so the .serials have changed and predict-. will need a rewrite
changed pr04.rkt to have a "main" so it'll be more useful for a module (eventually)
prettified on-new dump
out/functions-full.* are now gzipped
fixed the force logic and streamlined the updater (wasn't using on-prefer or such) now it should be that all timeout results are kept as "new" -- we'll see if this chokes the later generations or what.
updated to reflect new output format. e.g. the functions are a vector (of the four arities) of a vector (of complexities from 0..max) of lists of "pretty" function values.
fix. forgot to update arity 0 case
moving dump to beginning of extender call: the vector isn't "full length" until after extender returns so the results were shorter than computationally necessary.
changed the files to run from the command line. See usage.md for how to run them if you're not familiar with Racket.
darn copy paste bug.
started revision of notes to reflect new search.
tweaks
notes
entered the level 19+ results.
Merge branch 'keep-slow'

keep-slow has many updates/fixes that are now stable enough to get to depth 19.