show more recent questions bigger
don't show question number.
align answers to right; increase history table size
check for null or blank answers (lev/green crashes on empty strings)
hide number column 
example showing problem of incorrect answers which are mostly prefixes of correct answer
working on fixing blank guess problem.
in the process of fixing lost guesses
storing :children is what causes problems, so remove it.
use normal, not nowrap for whitespace
add some more useful expressions
move controls to the top
put guess and answer in the same column
renaming: shell->set, move functions to smaller scope.
cleanup
renaming
add path-in-order method
working on showing deletions (as well as inserts)
showing deletions and insertions seems to work pretty much.
don't show answer if it's identical to guess (user got it exactly right)