Update OOjs UI to v0.1.0-pre (23fb1b6144)

New changes:
41e01ca Add documentation explaining what's going on in GroupWidget
de8cd1d intro/outro: Keep local reference to OO inside closure
8bc207e Localisation updates from https://translatewiki.net.
5e1422e [BREAKING CHANGE] Use registry for tool group types
5d3ac51 Basic toolbar demo
ad53af5 Styling for disabled toolgroups
3529d6f Force visible label for MenuToolGroups

Change-Id: Ifdda408c17e257ffb3de2474bd64f5e2689e94d6
Merge "Update OOjs UI to v0.1.0-pre (23fb1b6144)"