Setting OPENBLAS_TARGET_ARCH should disable OPENBLAS_DYNAMIC_ARCH by default
update helpdb.jl
In \, only estimate rank and use complete orthogonal factorization for pivoted qr factorizations.
Merge pull request #8860 from JuliaLang/sf/openblas_dynamic_arch

Setting OPENBLAS_TARGET_ARCH disables OPENBLAS_DYNAMIC_ARCH by default
Small integer powers are no longer slow.

This has been fixed in issue #2741.
Merge pull request #8878 from ntessore/nt/doc-perf

Updated manual: Small integer powers are no longer slow.
Adapt to LLVM3.6 API change
Merge branch 'upstream-master'

Conflicts:
	doc/helpdb.jl