JuliaOpt/JuMP.jl — pull request #241 by joehuchette (2014-08-24 04:43:08+00:00)
Title: [WIP] Another iteration on JuMPDicts

I branched this off of #192 to try to add conditionals to indexing JuMPDicts. Here's a small example:

```julia
julia> @defVar(m, x[i=1:4, j=5:7]; iseven(i) || iseven(j), i <= 3)
x[i,j], for all i in {1..4}, j in {5..7} s.t. iseven(i) || iseven(j) and i <= 3 free

julia> x.indexsets
(1:4,5:7)

julia> x.conditions
2-element Array{Any,1}:
:(iseven(i) || iseven(j))
:(i <= 3)

julia> x.tupledict
Dict{(Any,Any),Variable} with 5 entries:
(2,5) => x[2,5]
(1,6) => x[1,6]
(3,6) => x[3,6]
(2,6) => x[2,6]
(2,7) => x[2,7]
```