updated to AIR 14.0.0.137
FeathersControl: if already initialized, initializeInternal() will return immediately
Text Renderers: initialize when measureText() is called, if needed, so that measurement will be accurate if a component is validated before being added to the stage (references #940)
Text Editors: initialize when measureText() is called, if needed, so that measurement will be accurate if a component is validated before being added to the stage (references #940)
Text Renderers: some optimization of previous commit (closes #940)
Text Renderers and Editors: set some things to null in dispose() to help free up particularly expensive memory (like native filters) if there's a memory leak (closes #941)