Twenty Fourteen: JavaScript fixes after running jshint, see r25960:

 * Enforce `===` instead of `==`
 * Fix confusing use of `!`
 * Remove unused variables like `calcNext`, defined but never used
 * Proper use of braces
 * Move functions out of if/else statements
 * Document unknown functions as Microsoft-specific

git-svn-id: https://develop.svn.wordpress.org/trunk@25995 602fd350-edb4-49c9-b593-d223f7449a82