Work on vendor API abstraction, and near complete Safari support
Alphabetical order for keys in Safari's Info.plist
Minor changes

- Update assets from gorhill/uBlock/master
- Remove whitespace from element-picker.js
- Simplify code in profiler.js (btw, Date is still needed as fallback
  for older browsers)
- Clarification for Safari's storage where the QUOTA_BYTES came from
Add .jshintrc, and use the "use strict" directive

.jshintrc's otion-set is a personal choice, merely a suggestion.
Beside that, it includes some common globals for specific browsers, so
there's no need to set the globals in every .js file.

In order to force strict coding, "use strict" directive was added into
every .js file.
Safari shows integers only over the toolbar icon
Remove storage change-event listener from Safari

Earlier, a technique was used to open the extension's Options page when
the user clicked a checkbox input at Safari's extension settings. The method was removed because:
- the Options page can be opened via the extension's toolbar button (which
  cannot be disabled in Safari, so it will be there all the time);
- involved more clicks than opening from the toolbar button;
- the string beside the checkbox couldn't be localized.
Move vAPI into .jshintrc as a global
Fix "invalid token" exception in Safari

Seems like in older versions the const keyword doesn't play well with the "use strict" directive
Implement popup autoresizing for Safari

By default, Safari doesn't resize the popup to its content, but it's
possible to set the size pragmatically.
The popup will be resized every time when a change happens in the DOM tree.
element-picker fixes, changes

- Include latest changes from gorhill/uBlock/master
- Append the pickerRoot container to document.documentElement instead
  of document.body ("body > div" type CSS selectors are more common, so
  they could overwrite the extension's styling with higher probability)
- Request localized strings from the background script instead of using
  the i18n API in content scripts
- Fuse element-picker.js' message handling into contentscript-end.js', since
  only one messaging channel can live at a time in a content script
Script injection, element picker, messaging

- Add script injection to vAPI, plus a raw implementation for Safari
  (element-picker.js requires it)
- Tweak element picker to work with Safari
- Revert a change from previous commit: element-picker.js' background
  message handler (since actually it can have its own messaging channel)
- Don't send "undefined" reponses from background to content
Use extension API to open links from the popup

Safari doesn't seem to follow links embedded in the popup window (not even
with target="_blank").
Remove unnecessary comments
Set default dimensions for Safari's popup
Use HTML5 download instead of extension API

Benefits:
- Cross browser solution (however only for relatively new browsers)
- Doesn't need extra permission in Chrome

If the browser doesn't suppor the download attribute, then a new tab will
be opened with the exported data.

Other changes:
- Start the download only if the data is not empty (previously the
  download started anyway)
- Reorder code in vapi-client.js for Safari, so unnecessary code doesn't
  run on extension pages
Use a dedicated file for storing extension info

Chrome has getManifest(), Safari doesn't have anything, Firefox has an
asynchronous API...
So, instead of using extension APIs, store the common informations
(extension name, version, homepage url) in a file (vapi-appinfo.js), which
can be included when it's needed (its data will be available at vAPI.app.____).
The file's content is updated each time the extension is being built, so
it shouldn't be modified manually.
Fix download URL for the fallback method
Workaround for a messaging bug in Safari
Use utf-8 for data: URIs when downloading
Avoid using Chrome's @@bidi_* type i18n messages

... for the sake of portability.

When including vapi-common.js in an HTML file, then the body element there
will have a "dir" attribute filled with the current locale's direction
(ltr or rtl).

The following languages are considered right-to-left: ar, he, fa, ps, ur.
Everything else is left-to-right.

After the "dir" attribute is set, we can decide in CSS which elements
should have different styling for rtl languages (e.g., body[dir=rtl] #id).