Comment cleanup & trailing whitespace removal

Attached patch:

1. Standardizes comments.
2. Removes trailing whitespace (except in multi-line query strings where it is retained for maintainability).
3. Removes hook_update_N() from Drupal 4.7 or earlier and replaces them with hook_update_last_removed().
4. Passes coder on "minor" (aside from the aforementioned trailing whitespace in query strings).