[SMLRCallViewController] added logo animation for incoming call
[SMLRCallViewController] added circles animation for incoming call
[SMLRCallViewController] incoming call animation: start/stop functions
[SMLRCallViewController] make sure incoming call animation is not started twice
[SMLRCallViewController] start incoming call animation when becoming active
[SMLRCallViewController] make sure incoming call animation only start when visible
[SMLRCallViewController] incoming call animation: circle and log animation start at the same time
[SMLRCallViewController] circle animation: maskToBounds
Merge pull request #10 from simlar/pullrequest-incoming-call-animation

Pullrequest: Incoming Call Animation