Documentation tweaks (`map!()` and `names()`)
Fix JuliaLang/julia#6665

Provides airyx in addition to bessel[jyikh]x
Tweaks to StepRange: Take 2
Updates following discussion in JuliaLang/julia#6665

Rather than introducing bessel[hijky]x functions, introduce optional
positional argument to bessel[hijky] and airy for scaled version.
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
improve scale! using a cutoff threshold for calling BLAS
BLAS cutoff for vecnorm* functions
better rearrangement of try/catch block in open(f, cmds)
Update parallel-computing.rst

minor edits in first example in parallel-computing.rst to switch from deprecated usage of '+' to '.+' for scalar-array addition.