Update VE core submodule to master

New changes:
16eb2e2 Script to update the oojs-ui and oojs distributions
b20be0b Fix exception thrown by findEndOfNode
af4f8f1 Fix Document#selectNodes error documentation
37ace2e Update OOjs to v1.0.6-pre (e284c5fed7)
2eb5927 Add internalList nodes to example data
461deca Fix up result of selectNodes
34fe23e Protect RDFa attributes from obliteration
4d562ec Resolve URLs against correct document when copying.
bc5be2a Adding a MediaSizeWidget

Change-Id: I903cd23a5244766df714ffd3232de1a031472c2a