Whitespace cleanups

Changes based on Code Review's Style mode.
Mostly whitespace changes as I ignored some things it suggested, like using drupal_strtoupper() instead of strtoupper(), to avoid potential logic changes.

Much of it is changing tabs to double spaces and removing trailing spaces, which may be difficult to spot in the patch, but git diff shows them nicely.

Might conflict slightly with my Comment cleanups patch but shouldn't be difficult to reroll.