Documentation tweaks (`map!()` and `names()`)
Tweaks to StepRange: Take 2
Force OpenBLAS to have a more sane GEMM_MULTITHREAD_THRESHOLD
add unicode superscripts and subscripts to latex substitutions
replace \\Elzxh with \\hbar to match latex usage
moved super/subscripts and hbar to manually added section
get rid of curly braces in latex super/subscripts and add \del mapping
Added StackOverflow link on README.md

I think StackOverflow is a very good platform, and helps expose Julia to a broader public. Putting a link here on the README should direct users to post more questions there.

Now, Julia is not very present at StackOverflow, and users might have the wrong impression that nobody uses the language or care about it. After all, the julia-users list is full of questions and nice answers.
support many more Unicode infix operators
Added "external resources" section, with links
Merge branch 'master' into sub_super
Add docs for short forms of reduce and fold
eliminate a couple more confusables; multiset multiplication U+228D should have * precedence despite looking like a union; change NEWS table to only explicitly list operators that are predefined
deprecate readsfrom/writesto in favor of simply using open on AbstractCmds, and support: open(cmd, mode) do io ... end
better rearrangement of try/catch block in open(f, cmds)
Check for definiteness in generalised eigensolvers. Use I in eigs. Change default nev in eigs because different restrictions apply to symmetric and non-symmetric problems. Use factorize instead of lufact for inverse operations.
Update Mac juliarc.jl (fixes #6880)

git (bundled in ROOT/libexec/git-core) isn't included on the PATH used by Julia. This causes issues on OSX when using the package manager because GIT_EXEC_PATH does point to the bundled git tools. By adding git-core explicitly, all issues are fixed. The bundled git is used throughout.
fix #6977, trying to allocate arrayvar for Array{None}
Merge pull request #6932 from brk00/patch-1

Added StackOverflow link on README.md
fix #6966