Update VE core submodule to master (c81252c)

New changes:
08d1b0b Alignment icons
0e418e8 Update constructors of inspectors and dialogs as per changes in I345d6e6
c81252c Update OOjs UI to v0.1.0-pre (e1b23620c0)

Change-Id: I6e904dcce0116c34373fda4a8fe86f7603bfea59