Add generalized repmat function as repeat
Document repeat function

Extend ind2sub and sub2ind to accept a reusable array of indices
Expose rem1 and fld1, defined by analogy with mod1
Restore basic ind2sub definition
don't require subclasses of AbstractVector/Matrix to implement more than 1d/2d indexing
pkg2/resolve: add prerelase/build in VersionWeigth

this will allow to remove filtering of prerelease/build versions,
and "normalization" of packages requirements which was introduced
in 0fa84ec69f060cc492772b1a1707eff3745675bf
pkg2: reinstate prerelease/build versions

Prerelease/build versions can again be used in "require" files.

This essentially reverts commits
0fa84ec69f060cc492772b1a1707eff3745675bf
923e385d029b22df67739f7f1de6df18721d2f97
pkg2: more tests in resolve2

For the new weighting scheme. Also, sanitize previous
tetst a little.
renamed finfer to code_typed
added code_lowered
renamed disassemble to code_llvm and code_native
unexport a bunch of Base modules (closes #3924)
Doc typo (thins -> things)
Update contributing.md (switch to "master" branch before editing)

Hi, the instructions didn't work for me and I found out I needed to switch to the "master" branch.  Hopefully this is the right branch for people to make edits.
fix #3506
Pick reasonable defaults for OpenBLAS threads on different architectures,

Also see: https://github.com/xianyi/OpenBLAS/issues/274
document exceptions, operators, constants, ccall types, internals,
syntax
sending privhost for worker interconnections
Merge pull request #3940 from amitmurthy/amitm/privfix

sending privhost for worker interconnections
We don't need to ask for JULIA_BRANCH or JULIA_DATECOMMIT anymore
Merge pull request #3898 from carlobaldassi/pkg2moreweights

Pkg2: reinstate prerelease/build versions