Merge pull request #34 from mnemnion/v1.2

V1.2 enlive visualizer added
Added some error handling
Tree detection and test cases
Merge branch 'v1.2' of https://github.com/Engelberg/instaparse into v1.2
normalizing local fork
change label test in tree-viz to match vec-of-vec or list-of-list
 On branch v1.2