symbols and text galore
fast-string helps performance a ton
add simple print-parse inverse property
add xmonad example
add XMonad.StackSet invariant
add benchmark for XMonad.focus_left_master
checking property that LH cant prove
messing with benchmarks
s/symbol/variable/
add Data.Map example, generating and checking that trees are balanced
add more tests for Data.Map
add failing tests, now to make them actually fail..
fix map neg tests
add another test for RBTree
add ByteString
add set_mem
add initial support for generating functions.

generating arbitrary values atm, need to constrain based on input
add examples/Expr.hs, generating closed terms.
dont bother with th
try fixing travis