Update OOjs UI to v0.1.0-pre (efc7297353)

New changes:
3ab4d6d Balance margins around icon on iconed ButtonWidget
8d69f53 Add missing 75% transparency to add-item
2c0ae23 Add indicators to demo page
1700e98 Localisation updates from https://translatewiki.net.
262cb8d Localisation updates from https://translatewiki.net.

Change-Id: If265e4760b69957a1cc0138f9834ea984763f1f8
Merge "Update OOjs UI to v0.1.0-pre (efc7297353)"