bootstrap table can't deal with uneven table

[mcampos-quinn]

currently the batch compare by field set template allows for table rows with an arbitrary number of tags. Bootstrap table balks at this and doesn't allow search/pagination.

Proposed solution is to fluff the comparison dict returned by batch_compare.py batch_compare_{field set}() with extra empty data values so the table can be nice and square.

Accomplish by counting the max number of columns in a given row after the dict is complete and fluff out any row dicts that are short.