Redirect stderr from which

This avoids `which: no fetch in ($PATH)` messages when downloading dependencies. These can get pretty long.
Add quotes and an informative error message

Since [ -x  ] is true, but [ -x "" ] is false
Add more unit tests for test/random.jl in preparation for refactor
Merge pull request #5993 from jperla/master

Add more unit tests for test/random.jl in preparation for refactor
Change generalized svd to return Q and R separately. Update docs to point to svdfact and eigfact.
Reverts deterministic test of MersenneTwister. Closes #5999

The hardcoded value turns out to be platform specific.
Fix matrix * and \ for errors reported in #5953
Merge pull request #6007 from JuliaLang/anj/matvec

Fix matrix * and \ for errors reported in #5953
Merge pull request #5972 from tkelman/patch-1

Redirect stderr from which
fix #5904, assertion failure running pipelines

must be careful using functional constructs where side effects are needed
Merge branch 'master' of github.com:JuliaLang/julia
FloatRange: move the .divisor field to the end.

The initial fields match the field of Range this way.
Merge pull request #5941 from JuliaLang/anj/svd

Change generalized svd to return Q and R separately. Update docs to point to svdfact and eigfact.