Taxation; Prohibiting counties, municipalities, and special districts, respectively, from levying certain special assessments against more than a specified square footage amount per recreational vehicle parking space or campsite; revising a specified finding that a taxing authority must make in order to elect not to exempt certain property from certain ad valorem taxation; exempting certain liquefied petroleum gas tanks from sales and use tax; revising the conditions required for a county to be considered a fiscally constrained county, etc.