change "get started" message
fix some js bugs relating to stoichiometry table
stop backspace key from navigating back on edit page.
don't try to set units to 'undefined' selection
add rounding to equiv field in stoic table
bugfix
bugs - improve unit handling and make tag/link add/delete work right
in add product box, give name as "unknown", not "undefined", when unknown.
improve handling of limiting reagent
don't use decimal type in db, just stick w/float.
when purity changes in product table, update yield/mol.
fix database handling of wt%