Always copy bootstrap and destroy in extension
Add PDF.js assets to the Chrome extension

This comes from PDF.js v1.0.473, generic build, with zero modification.
Remove unwanted 1M sample PDF
Insert H code into the PDF.js viewer html
Fix URI and metadata handling for PDF documents

 * Don't load the Document plugin for PDF files; Annotator's PDF plugin
   provides the fuctionality (uri+metadata extraction) in these cases.
   Use async metadata extraction for PDF

 * Updated PDF plugin to fcdf1eac (pdf-update branch)
When displaying annotations, avoid non-clickable URIs
Modify background.js for PDF.js

inject and remove logic has been modified to handle
PDF.js differently.
Update Chrome extension manifest.json

Remove a bunch of useless permissions,
update a few filenames
Removed obsolete links to sourcemaps
Merge pull request #1563 from hypothesis/1334-pdfjs-6

[WIP] add support for packaging with PDF.js extension - try 4