Move LESS function definitions from DefaultSettings to ResourceLoaderLESSFunctions.php

Intermittent error in production from top-level lambda functions:
https://bugs.php.net/bug.php?id=52144

Change-Id: I9785a601fd5d57c9d8d84b90ee29eef61a6f2e77
Merge "Move LESS function definitions from DefaultSettings to ResourceLoaderLESSFunctions.php"