New Data Table Features

[Dave Leip]

I have added an additional feature to manipulate the data tables.  Everyone can change the visible columns for the national (state-level) data tables.  View population, registered voters, voter turnout, voting-age population, etc. or disable certain columns to fit your need.  Also more sort options, such as population, turnout, etc.  Members get the same functionality for county, town, and precinct data as well as the ability to select minimum percentage of votes for candidates to have their own percentage and vote columns.  Let me know what you think.