Update OOjs UI to v0.1.0-pre (26dadbc60f)

New changes:
6c91643 Make buttons respond to :active events
9137aaf Move window overlay up to be a sibling of the frame
19d8c83 ComboBoxWidget: Append menu to $overlay option
eb0fcb8 InlineMenuWidget: Fix documentation
19d2c2b SelectWidget: Fix typos in documentation
495d281 TextInputMenuWidget: Fix typo in documentation
b4ae961 Toolbar: Correctly display "More" label on catch-all groups
32e769e Toolbar demo: Fix tool name mismatch
e9983b6 build: Clean up Grunt config and add missing csscomb run

Change-Id: I1ee2e51460c709fa01934ae7d58ac8411b124867