Fixes but 960409 and adresses review comments including removal of do-while construct
Refactors shared/pattern.js into core/ and display/
[CRX] Support <embed type="application/pdf">
[security] Verify message source in Firefox add-on

And put initPassiveLoading within a preprocessor block because
it is only used by Firefox.
Merge pull request #4197 from Rob--W/firefox-verify-message-source

[security] Verify message source in Firefox add-on
Fixes smask backdrop
Removes button outline as visible in Chrome
Merge pull request #4203 from timvandermeij/outline-chrome

Removes button outline as visible in Chrome
Merge pull request #4194 from Rob--W/crx-pdf-embed

Support <embed type="application/pdf"> in Chromium extension
Merge pull request #4201 from yurydelendik/smask-backdrop

Fixes smask backdrop
Merge pull request #4189 from yurydelendik/split-pattern

Refactors shared/pattern.js into core/ and display/
Merge pull request #4131 from karlden/findUnboundedRecursionBug960409

Fixes find functionality recursion (bugzilla FF bug 960409)
Refactors nextPageMatch (nits)
Merge pull request #4210 from yurydelendik/issue4131

Refactors nextPageMatch (nits)