Added `typeof` test against `module` to preamble.
Added `typeof` test against `module` to preamble.

Without the `typeof` test, an exception is raised because `module` is
undefined.

    File                             Raw         Min         Zip     Min/Zip
    rfc822.js                 8164/07.97  3141/03.07  3452/03.37  1572/01.54

Closes #94.

bigeasy/timezone,bigeasy/timezone,bigeasy/timezone