use isContra instead of just checking for PFalse
Merge branch 'master' of github.com:ucsd-progsys/liquid-fixpoint
many misc tweaks, hopefully nothing breaks
checkValid seems to be working
misc tweaks to use real temp-files
Merge pull request #5 from gridaphobe/master

add `-lrt` to get fixpoint building on goto again
Merge branch 'master' of github.com:ucsd-progsys/liquid-fixpoint