Fixes cmap sanitizer fro #215
Scroll the Thumbnail of the current page into view when exiting fullscreen mode
Fix issue with 'this' binding in PdfStreamConverter
Rewrite and refactor getVisibleElements() to make it more generic - address comments by @brendandahl
Handles embed tags via PlayPreview API
Fix the calculation of default vertical metrics

Fixes bug 849627 and 849628.
The current code was obviously wrong per the spec 9.7.4.3.
Merge pull request #2932 from vyv03354/bug849627

Fix the calculation of default vertical metrics
Store references as pngs and write failures to separate png files.
Merge pull request #2920 from Snuffleupagus/thumbnail-on-fullscreen-close

Scroll the Thumbnail of the current page into view when exiting fullscreen mode
Merge pull request #2935 from brendandahl/png-refs2

Store references as pngs and write failures to separate png files.
Add basic support for transparency groups.
Use relative paths for ref images and copy refs.
Merge pull request #2940 from brendandahl/ref-fixes

Use relative paths for ref images and copy refs.
Merge pull request #2927 from mduan/fix-this-binding

Fix issue with 'this' binding in PdfStreamConverter
Add back cid cff font test.
Merge pull request #2942 from brendandahl/add-back-cid

Add back cid cff font test.
Remove mozOpaque.
Ignore test snapshots directory.
Merge pull request #2950 from brendandahl/ignore-snps

Ignore test snapshots directory.
Implement "B5pc-H" CMap