3.0 release!

Big changes in this massive release to 3.0 (and beyond)! A new
background for the dialog boxes, double-check area in the second
Proofing window, and error checking for spaces in required fields, plus
plenty of bug fixes!

Output.jsx:
* Reset measurement units to Auto upon script start.
* Fixing double-sided MiniPad printing, so only the side(s) that
has(/have) the correct dimensions will be printed.
* Cosmetic change to “Please Wait” windows so they are now flat.
* Forced Mini-Pad document to be measured in Inches.
* Fixed some text not outputting on Mini-Pad film.
* Fixed artwork’s dimensions on diagonal napkins being read incorrectly.
* Small amount of code cleanup.
* Various other bug fixes.
* Increased version number up to v3.04

Proof.jsx:
* Added double-checking area to second dialog! Now you can make sure
that all of the customer-specific information was entered correctly
before the automation begins!
* Added check to make sure that whitespace is not allowed in required
fields, such as Quantity. (It *must* contain a non-whitespace
character.)
* Increased version number up to v3.02