Update VE core submodule to master (7a128e5)

Fix failing test in handleDelete. New functionality
moves cursor to content offset.

New changes:
fb595ea Also annotate metadata in TransactionProcessor
028e442 maintenance: Simpler OOjs UI pullthrough-script
fdd5e17 Follow-up I81663929: Use grunt git-build to ensure we get the hash
58db9a8 Update OOjs UI to v0.1.0-pre (a63f03882e)
c790488 Use more standard format for displaying keyboard shortcuts
c15a6f1 Add a ve direction class to all surfaces
5c3a914 Remove old ce-surface classes
2f565b6 Fix up selection after deletion if at non-content offset
7b39328 Correct various things in rangy-position to make it work in IE

Change-Id: Ia46f4c7ded52911574b6c1104682335aaaac08d5
Merge "Update VE core submodule to master (7a128e5)"