Another bugfix and small enhancement release!

Fixed

• SmartResize takes invisible columns into account (https://github.com/edvin/tornadofx/issues/889)
• radiomenuitem didn't store value parameter properly (https://github.com/edvin/tornadofx/issues/737)
• fitToWidth/fitToHeigh binds prefWidth/prefHeight instead of minWidth/minHeight properties (https://github.com/edvin/tornadofx/issues/886)
• menu/item builders now observes FX.ignoreParentBuilder
• Renamed labelProperty to textProperty in AbstractField
• Wizard next button was enabled even when current page was not complete (https://github.com/edvin/tornadofx/issues/960)
• App primary view would continue to receive onDock/onUndock after its app instance was stopped and out of scope (https://github.com/edvin/tornadofx/issues/973)

Changes

• Opened up HttpClientEngine and HttpURLEngine for easier subclassing/configuration of the Rest engine
• Deprecated observableList() in favour of observableListOf(), and [List, Set, Map].observable() in favour of [List, Set, Map].asObservable() to be consistent with the Kotlin standard library.