use Number.isFinite instead of isInt in FSChange widget, consolidate code with...

use Number.isFinite instead of isInt in FSChange widget, consolidate code with FSChangePorn widget by adding optional third arg (multiplier) for FSChange; add new widget ValidateFacilityDecoration; consolidate ClearFacilityDecorations widget code using new validate widget; similarly consolidate code in futureSocities using new validate widget