rename methods of min and max that do reductions to minimum and maximum

this is step 1 for #4235
Merge branch 'master' of github.com:JuliaLang/julia into jb/minmax
step 2 for #4235

make minimum and maximum use scalarmin and scalarmax, which are min
  and max but exclude arrays

remove isless for AbstractArray

add LexicographicOrdering and use it in sortrows and sortcols
currently LexicographicOrdering is implemented with cmp(), which does
  the right thing for arrays, but we might not want to keep it that way
update release notes for min/max changes
Merge branch 'master' of github.com:JuliaLang/julia into jb/minmax
Update README.windows.md
allow serializing Tasks that are done or haven't started yet. fixes #4516
sorting: use `@inbounds` to eliminate bounds checks.

Shaved of 7% for sort and 25% for sortperm.
add lexcmp and lexless for lexicographic comparison

step 3 of #4235, closes #4235
Merge branch 'master' of github.com:JuliaLang/julia into jb/minmax

Conflicts:
	base/ordering.jl
update directory descriptions in README
Close #3291
Merge branch 'master' of github.com:JuliaLang/julia
Further changes to eigs

(1) ARPACK info flag 1 now results in a warning (maximal number of
iterations taken) rather then throwing an error.
(2) Added the return value nconv, indicating the number of converged
eigenvalues, which is relevant when the maximal number of iterations
has been taken before all requested eigenvalues have converged (which
no longer leads to an error thanks to (1) ).
(3) Modified behavior of eigs such that any input type of matrix is
allowed, as long as the type of A overloads the methods size, issym,
eltype and can be multiplied with a vector of the same element type.
(4) Updated test file accordingly
Update README.windows.md

p7zip-full works on ubuntu
Merge branch 'master' of github.com:Jutho/julia into Jutho-master

Conflicts:
	base/linalg/arnoldi.jl
Merge branch 'master' of github.com:JuliaLang/julia
Fix indentation. Remove old svds implementation.
sorting bounds checks: wrapping a function definition does nothing.

Sortperm on Float64 arrays is now 37% faster than it used to be since
I've actually removed the bounds checks in nans2left and nans2right.
I tried various ways to wrap the lt(::Perm,a,b) call in `@inbounds`
but all approaches caused significant slow downs.
Merge branch 'master' of github.com:JuliaLang/julia

Conflicts:
	base/ordering.jl