DataFrame(d::Dict) trying to access d(:key).
added sort to column names, added test.
added sort!(dames)
removed DataFrame(d::Dict) and deprecated with a call to convert(::DataFrame,d::Dict) - which is basically the constructor from before.
used depwarn() incorrectly. still breaks test/dataframe.jl? not sure how that relates to my changes...
added conversions to runrests.jl
removed tests for deprecated constructors.
Merge pull request #626 from floswald/DataFrameDictConstructor

DataFrame(d::Dict) trying to access d(:key).