Update VE core submodule to master (fb57e24)

New changes:
7d8ed7f Copy in some IE CSS hacks from ve-mw
a2e962e Update OOjs UI to v0.1.0-pre (20c61ec865)
d99c62f Update OOjs UI to v0.1.0-pre (d4cfcce969)
7fe02b3 Fix lots of spelling mistakes and typos

Local changes:
Remove redundant IE CSS rules since core's I013688c5

Bug: 73565
Change-Id: Ic60cd5290932ec38fab26492fffa17c3a8e91398