Re-indent test files.
Fix customizer.js indentation warnings.
Document caveats of `pointer-events: none` usage in btn.disabled

Refs #10049
Source for compatibility info: http://caniuse.com/#feat=pointer-events
Merge pull request #12720 from twbs/reident-test-files

Reindent test files
Safari rounding problem still present as of v7.0.1 for OS X
Merge pull request #12749 from twbs/pointer-events-note

Document caveats of `pointer-events: none` usage in btn.disabled