JuliaLang/julia — pull request #1738 by binarybana (2012-12-12 16:19:03+00:00)
Title: Add pop and isless to sets

Tests also added in test/corelib.jl.

Short example:
```julia
origs = Set(1,2,3)
s = copy(origs)
el = pop(s)
# has(s, el) == false
# has(origs, el) == true
# s < origs == true
# s <= origs == true
# s > origs == false
```