nice-ify histogram ranges, use range algorithm
fixed tests, renamed histrange
one-line midpoints, fix arrayops test
simplified histrange calculation, added help
typo in hist doc
include egdes in return value, resolve #2335
wip: Pkg rewrite -- version interval algebra.
pkg2: move from base into extras while under development.
versions: add "supremum" pseudo-versions like v"1.2.3+".

Introduce typemin and typemax methods for version numbers.
Merge branch 'master' of github.com:JuliaLang/julia
Merge branch 'master' of github.com:JuliaLang/julia into jb/kwargs
show typemax(VersionNumber) as v"∞" (not valid input syntax).
pkg2 wip: much simpler intersection of version sets.

This does away with the VersionSet type in favor of VersionInterval
and uses vectors of VersionIntervals to represent sets of versions,
i.e. a union of an ordered series of disjoint version intervals. The
typemin and typemax methods for VersionNumbers greatly simplify this.
Merge pull request #2687 from simonbyrne/hist

RFC: nice-ify histogram ranges, use range algorithm
add some basic documentation on optional and named arguments
Merge branch 'master' of github.com:JuliaLang/julia into jb/kwargs