Fix doc status of dropPinnedRow, add cancelPinnedMode, update sample to support cancellation

Enyo-DCO-1.1-Signed-Off-By: Ben Combee (ben.combee@palm.com)
Support reordering without pinned mode, switch sample to not use pinned mode for now as we're considering it a WIP feature for Enyo 2.2.

Enyo-DCO-1.1-Signed-Off-By: Ben Combee (ben.combee@palm.com)