JuliaStats/DataFrames.jl — pull request #728 by tshort (2014-11-23 23:22:17+00:00)
Title: Fixes for SubDataFrames to better support AbstractDataFrames.

These changes should allow `sub` and SubDataFrames to work with other AbstractDataFrames.

I don's have another AbstractDataFrame to test it on here, but DataFramesMeta has CompositeDataFrame.