Fix JuliaLang/julia#6665

Provides airyx in addition to bessel[jyikh]x
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.
automatically NULL-terminate UTF16 data for passing to Windows (and similar) APIs
NULL-terminate UTF32String data for consistency; deprecate UTF32String(c::Char...) in favor of utf32(c...); add conversion to UTF32String from binary data that looks at the BOM
NEWS updates for UTF16String and UTF32String
added utfXX(ptr[,len]) functions analogous to bytestring, added WString and wstring aliases to make wchar_t* APIs usable
fix utf32/UTF32String mixup
add deprecation for UTF32String(s::String)
avoid deprecation warning in converting UTFxxString to equal-sized integer types
type typo (and regression test) in utfXX(::Ptr{IntXX})
return a Failure instead of rethrowing an expection in @test_throws
See: https://github.com/JuliaLang/julia/issues/7051
cosmetics: remove tab, fix alignment
add unit tests for Base.Test. Missing tests for @test_approx_eq, but will open discussion with an issue.
readdlm has_header is now header, skipstart added

fixes #6869
- `header` takes a boolean value and behaves like `has_header` or DataFrames `header` option.
- `skipstart` takes a positive integer value and behaves like DataFrames `skipstart` option.
Improvements to regex performance.
Boundschecks for searchsorted & remove step(r::Range)==0 tests

1) Check bounds on the more low-level searchsorted* methods.  Before
an error like this was possible:
```
julia> searchsortedfirst([1:10], 5,  -10, 7, Base.Order.Forward)
zsh: segmentation fault (core dumped)
```

2) Removes the step(r)==0 tests as ranges cannot have 0 steps (I
   think)

Note that the low-level sort! methods also do not check bounds.
Probably this should also be rectified.
Fix for LLVM trunk changes that broke enableUnsafeAlgebraIfReduction.
generalize indexin definition
use static_show for errors during finalization
use correct uvfinalize method for PipeServer. fixes #7020

remove double shutdown check in jl_close_uv; fixed upstream.