Handle empty columns and rows

Problem/Motivation

I have found, especially with Excel, that sometimes when you save, several blank columns or rows will get added into your CSV. The presence of more than one blank column will throw and error about duplicated column names and prevent you from continuing to build your view.

Proposed resolution

Add a method to identify and exclude columns that are entirely empty. I think providing that feature would be helpful for rows, though that can potentially be mitigated by a filter.