map liquid to Ghc TyVars before quiantification
Merge pull request #69 from gridaphobe/master

set hard constraints on package versions
Merge pull request #64 from ucsd-progsys/tyvar_subst

Tyvar substitution
tidy renameTyVars
edits tests
adding zipper example, focus passes
all zipper functions verified
zipper:integrate'
add initial stackset
qualify Set
rename data con arguments
tagBinder now passes
allow many type specifications, seperated by comma
assumes for integral