Update VE core submodule to master (5092503)

New changes:
2bd4437 Check target container is attached to ownerDocument
9620ea1 Localisation updates from https://translatewiki.net.
816e5df Update oojs to v1.0.7
975183e Upgrade UnicodeJS to Unicode 6.3 spec
0eedc9b Localisation updates from https://translatewiki.net.
1fc0d04 unicodejs: Make tool executable, fix path
5092503 Use new jscs options, disable deprecated JSHint checkstyle options

Change-Id: Ic549221c86a83c88c2c15c49ec969abe30e2dd17