Enhancement: image 'Alt Text' is now included on IMGs
begins the cleanup necessary to catch PMJS up to PMWP
concats JS (jquery, jstween, prettphoto) into photomosaic.js so we can load fewer files
 - catches PMJS up to PMWP
 - fixes PMJS-only stuff that I didn't worry about when working on PMWP
 - backfills those fixes to PMWP to keep things in sync
 - updates PMJS docs
 - adds and improves some error messages
 - syncs changes between PMJS, PMWP, and PMDEMO
updates PMJS download