Docs: Dict{K,V}() instead of Dict{K,V}(n)

Dict does not seem to take an initial size any more:

    julia> x = Dict{ASCIIString,Any}(10)
    ERROR: no method Dict(Int64,)




    julia> x = Dict{ASCIIString,Any}()
    Dict{ASCIIString,Any}()
Merge pull request #2227 from rened/patch-1

Docs: Dict{K,V}() instead of Dict{K,V}(n)