HarlanH/DataFrames.jl — pull request #317 by mweiden (2013-07-11 12:19:54+00:00)
Title: RFC: Only columns of strings should be made factors.

As I understand the spec and the outline of the the readtable method code,
only columns of data files that have all strings should be made into factors
given that the makefactors boolean in the method is active.

This logic is implemented here.