postprocess can now return Parser.fail

when a rule completes, the post processor may now provide a semantic
pass/fail to provide the last word on if the completed rule was a
successful parse
add a couple tests
fixed start bug
Merge branch 'rwindelz-post-process-as-predicate-2'
document that change
1.2.0
Nathan and Jacob go in the module credits
prettified the website
basic AST visualization
what are we doing
added fuzzy parsing