improved matching algorithm

- handle growing matching area together with unchanged screenshots
- search whole area every 6 seconds
tidy fix
decrease load for short timeouts

- delay full search by 5 seconds, this decreases load for short
timeouts with needles matching at original position
Merge branch 'master' of https://github.com/nadvornik/os-autoinst into nadvornik-master
Merge branch 'nadvornik-master'