eyenfinger: added delayed drawing to captured screenshots

if iSetDefaultDelayedDrawing(True), then inputs are not immediately
illustrated in captured images. Instead, draw commands are recorded to
screenshot.delayeddraw files. Commands can be evaluated after test
runs, resulting in faster test runs.
fmbtandroid: supportsView() added, garbage collector helped

supportsView() returns True if refreshView() and other keywords using
view data are supported on the platform on connected device. When
fmbtandroid.Device() object is not referred by any variable, it
immediately disconnects from the device.