Update VE core submodule to master (8d5ec7a)

New changes:
8d5ec7a [BREAKING CHANGE] Rename ve.Document.getNodeFromOffset to getBranchNodeFromOffset

Local changes:
* Update calls for rename of getNodeFromOffset to getBranchNodeFromOffset

Change-Id: Ibc69f5a5deeed5698368bb19b30f14497c579e90