lexically sort keys in tocsv, tohtml, and totable if no order is specified

On perls with hash randomization (>= 5.18) this makes UTs pass and makes for a nicer
user experience (columns don't randomly reorder themselves).
Merge pull request #27 from elindsey/tofoo_sorting

lexically sort keys in tocsv, tohtml, and totable if no order is specifi...