take-screenshots profile added to ftest

- its a dependency for Graphene screenshooter, arquillian.xml configuration created
ftest: changes to work with screenshooter extension

- get rid of HTMLUnit Driver instantiation
- in all functional tests should be @Drone, added where missed
ARQGRA-450: TakeBeforeTest option fixed

- GrapheneContext can not be produced only once after screenshooter configured event, but it has to be retrieved after every Before event
- increased precedence for screenshooter observer for Before event, because it has to be invoked before JUnit @Before observers (essential in case the loading of the page is done in JUnit @Before method)