add extended pull content attribute and handlers for scroller.cmp
Merge branch 'jdonaldson/master/extendedPullContentRev2' of https://git.soma.salesforce.com/jdonaldson/aura into jtroup/master-pending-jdonaldson-scrollerPullRequest
Merging origin/jtroup/master-pending-jdonaldson-scrollerPullRequest into master