Bug 893269 - [dialer][contacts] wrong action will occur after opening the contacts through dialer and then tapping on a contact call log

https://bugzilla.mozilla.org/show_bug.cgi?id=893269

1. listen click events in oncall.js
2. remove redundant variable
3. remove mouseleave/touchleave event
4. detect key change by position when touchmove/mousemove (#829406)
5. add method un utils to get x/y position of mousemove/touchmove event
6. replace if else with switch in keypad.js