[CRX] Fall back to sender.tab.url if !tab.url

sender.url is relatively new (Chromium 29)
 ( https://chromiumcodereview.appspot.com/14301016 )
[CRX] Remove redundant location.origin check

The PDF Viewer will always be rendered directly from the extension,
so checking "origin == chrome-extension:/.." is not needed any more.
( since edd4bae903c36048b7d4d4bed393e4408d0198ba )
Register as File browser handler in Chrome OS
Do not switch to a range request for small PDFs
Merge pull request #4258 from Rob--W/network-reduce-requests

Do not switch to a range request for small PDFs
Removes -moz-box-sizing usage
Change test font to one that works with ttx v2.4.
Merge pull request #4272 from brendandahl/change-test-font

Change test font to one that works with ttx v2.4.
Update ja locale
Merge #4274
Merge pull request #4191 from Rob--W/crx-chrome-os

Register PDF Viewer as PDF handler in Chrome OS's file browser
Bug 972435 - Recompress all PNG assets
Merge pull request #4287 from gabrielesvelto/bug-972435-recompress-png

Bug 972435 - Recompress all PNG assets
Update cs locale
Merge pull request #4288 from deepj/cs-locale

Update cs locale
Corrected word spelling
Merge pull request #4291 from hugo53/patch-1

Corrected word spelling and made translation be right
Update cs locale
Merge pull request #4294 from deepj/cs-locale

Update cs locale
Fix for bind compatibility implementation (polyfill).

Previously, reconstruction of arguments was incorrect if arguments contained
arrays. Arrays were added to arguments as their elements and not as a whole
array. It is enough to simply pass whole array to concat and it will be (only
one level deep) added to arguments.

In addition, we call slice on arguments for maximum compatibility (it is used
in Underscore.js library, with which I was comparing implementations while
debugging).