removing the planned describe_query as this is not possible (see issue #17)
clean out crufty leftovers from app.py
variant view now shows alert if # of rows returned is > query limit.
clear alerts when re-rendering table
view_variants now displays alert message when # of rows returned exceeds the limit of the query. Also provides new optionsModal to adjust query limit. This (mostly) closes #10 (though advanced reloading/paging has been punted for now)
minor cleanup of unused vars