Update the embedded PDF.js code to v1.0.712

These files come straight from the generic build of PDF.js v1.0.712.

There are only two changes:

 - I did not include the 1M test pdf document
   (See https://github.com/hypothesis/h/commit/8c20039893c87da1e98743ee5b0fd5065b4b0a99 )

 - I have kept our 1-line code insertation in viewer.html.
   (See https://github.com/hypothesis/h/commit/da3469477cf0412a693c5a54a7e0ed6a952c43f0 )
Merge pull request #1595 from hypothesis/1594-update-embedded-pdfjs

Update the embedded PDF.js code to v1.0.712