Fixed exception in ScrollController when layout-function didn't have any capabilities
Made reflow on resize optional through option 'reflowOnResize' (default: true) + simplified various code
Force redraw when alignment is changed
Fixed FlexScrollView.getSpec which returned an exception
Replaced 'useContainerOverflow' option in favour of more generic 'container' options in which all options for ContainerSurface can be specified
useContainer to be used as container instance