Schedule the switch in the video timeline.
Schedule the switch in the video timeline.

Instead of always replacing the currentTime, only replace starting
at the currentTime for immediate switches.  Otherwise, use bandwidth
estimates to guess what the video currentTime will be when the new
segments have been fetched, and replace the old segments starting
at that point.

Relates to #51.

Change-Id: I0e8546402cb0f7a007a6c210ed3b215c8379e236

samdutton/shaka-player,sanbornhnewyyz/shaka-player,baconz/shaka-player,vpopolitov/shaka-player,samdutton/shaka-player,palmerj3/shaka-player,vpopolitov/shaka-player,intfrr/shaka-player,baconz/shaka-player,treejames/shaka-player,UIKit0/shaka-player,samdutton/shaka-player,treejames/shaka-player,brightcove/shaka-player,brightcove/shaka-player,samdutton/shaka-player,treejames/shaka-player,op1ekun/shaka-player,op1ekun/shaka-player,indiereign/shaka-player,TobbeEdgeware/shaka-player,palmerj3/shaka-player,palmerj3/shaka-player,blinkbox/shaka-player,UIKit0/shaka-player,sanbornhnewyyz/shaka-player,sanbornhnewyyz/shaka-player,viniciusferreira/shaka-player,russitto/shaka-player,Ross-cz/shaka-player,rodrigoramos/shaka-player,priyajeet/shaka-player,priyajeet/shaka-player,TobbeEdgeware/shaka-player,blinkbox/shaka-player,Afrostream/shaka-player,TobbeEdgeware/shaka-player,intfrr/shaka-player,indiereign/shaka-player,palmerj3/shaka-player,viniciusferreira/shaka-player,russitto/shaka-player,ustudio/shaka-player,ustudio/shaka-player,tvoli/shaka-player,blinkbox/shaka-player,vimond/shaka-player,Afrostream/shaka-player,tvoli/shaka-player,tvoli/shaka-player,TheModMaker/shaka-player,ustudio/shaka-player,viniciusferreira/shaka-player,vpopolitov/shaka-player,vimond/shaka-player,cmgrecu/shaka-player,TheModMaker/shaka-player,intfrr/shaka-player,viniciusferreira/shaka-player,rodrigoramos/shaka-player,rodrigoramos/shaka-player,op1ekun/shaka-player,Afrostream/shaka-player,Ross-cz/shaka-player,cmgrecu/shaka-player,TheModMaker/shaka-player,TheModMaker/shaka-player,op1ekun/shaka-player,vpopolitov/shaka-player,priyajeet/shaka-player,brightcove/shaka-player,cmgrecu/shaka-player,indiereign/shaka-player,Ross-cz/shaka-player,tvoli/shaka-player,UIKit0/shaka-player,intfrr/shaka-player,shaka-project/shaka-player,sanbornhnewyyz/shaka-player,russitto/shaka-player,shaka-project/shaka-player,shaka-project/shaka-player,priyajeet/shaka-player,shaka-project/shaka-player,Afrostream/shaka-player,UIKit0/shaka-player,rodrigoramos/shaka-player,blinkbox/shaka-player,ustudio/shaka-player,baconz/shaka-player,treejames/shaka-player,vimond/shaka-player