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
Adds expm(A::Hermitian)

Uses eigenvalue decomposition to compute expm(A). This is a stable method for
Hermitian matrices and is about 2x as fast in my testing.
Add test for Hermitian expm.
Adds tests of simple tridiagonal operations
Merge pull request #2656 from jiahao/symtridiag-tests

Adds tests of simple tridiagonal operations
Merge pull request #2631 from blakejohnson/hermitian-expm

Adds expm(A::Hermitian)
Merge branch 'master' of github.com:JuliaLang/julia into jb/tupletypes
a couple performance tweaks
some dispatch code tweaks
Remove old exports from exports.jl
Fix bug in return from stebz. iblock was not returned.
cut down on some specialization in inference.jl
Merge branch 'master' of github.com:JuliaLang/julia into jb/tupletypes
user can specify a llvm-config in Make.user when USE_SYSTEM_LLVM=1