jpegmeta: Add links to source version and improve documentation

* The closure added when this lib was imported included a jQuery
  reference, which is unnecessary.
* Remove "Starts here" and "Ends here" comments.
* Resolve the "no clue" comment.

Change-Id: Ia4b66be455e28981832a4bdd8e7d3cb290d94d54
Merge "jpegmeta: Add links to source version and improve documentation"