some work on #671. does not work yet.
new tuple type hierarchy working. #671
a couple fixes to new tuple type hierarchy
another small fix
Merge branch 'master' of github.com:JuliaLang/julia into jb/tupletypes
Merge branch 'master' of github.com:JuliaLang/julia into jb/tupletypes
Merge branch 'master' of github.com:JuliaLang/julia into jb/tupletypes
a couple performance tweaks
some dispatch code tweaks
Merge branch 'master' of github.com:JuliaLang/julia into jb/tupletypes