Update VE core submodule to master (a2ddd0c)

New changes:
aede196 Clear inspector fragment from teardown(), not close()
db3de1f Localisation updates from https://translatewiki.net.
3c97e56 Tests for ce.Surface#getNearestCorrectOffset
e1d9ab2 Localisation updates from https://translatewiki.net.
a2ddd0c Update OOjs UI to v0.1.0-pre (989950a4db)

Change-Id: Id0f163d56dd0a0f6dd27a3ec2a102b0a43b27319