Bug fixing only
make sure llvm finds 2.5 <= python < 3

On some systems python2 doesn't exist (e.g., freebsd10),
or python2 < 2.5 (e.g., centos5).
correct NEWS about readdlm
promotion: symmetrize promotion rules recursively with promote_type.

If promote_rule(T,S) and promote_rule(S,T) disagree, call promote_type
again on the results to get a single common answer. This can resolve
cases where there is a conflict between two such rules, making the
promotion system a bit more robust.
pretty-pretting of which and methodswith output
math constants: simplify and generalize promotion with constants.
Update contrib/debug_bootstrap.gdb
Merge pull request #4967 from simonp0420/amos_error_checking

Add error checking to Amos package-based Airy and Bessel methods. Correct # arguments in ccall to :zbiry.
further promotion rule simplifications
Update NEWS.md with error trapping of AMOS functions
fix missing roots for some boxed values in codegen (serious memory bug)
Merge pull request #5466 from JuliaLang/sk/promote

promotion: symmetrize promotion rules recursively with promote_type.
grammar in NEWS
Merge pull request #5464 from stevengj/prettymethods

pretty-pretting of which and methodswith output
Merge branch 'master' of git://github.com/JuliaLang/julia