v0.5.0

• New syncClass feature for synchronizing classes with state. Use this to automatically add/remove classes according to checkbox or radio button statre.
• Add support for removing specific inputs via removeElement/removeElements. Sometimes it's easier to add all inputs and then remove ones you don't want to track.
• API now exposes getInputEvents in case user wants to override which events to listen to.
• Furls input objects now have a type field, making it easier to distinguish different sorts of inputs/textareas.
• Prevent namespace leakage: window no longer gets polluted with getParameterByName, getInputValue, getDefaultInputValue, setInputValue, getInputEvents.