Add initial blaze type unification algorithm
Add initial blaze type unification algorithm

cowlicks/datashape,blaze/datashape,llllllllll/datashape,FrancescAlted/datashape,FrancescAlted/datashape,aterrel/datashape,quantopian/datashape,markflorisson/datashape,cpcloud/datashape,markflorisson/datashape,blaze/datashape,ContinuumIO/datashape,aterrel/datashape,quantopian/datashape,llllllllll/datashape,ContinuumIO/datashape,cpcloud/datashape,cowlicks/datashape