Add scan for media gallery functionality.
Update gapi-chrome-apps.js

JSON.parse("") throws an error, however some Google APIs return a blank response for success.  Ran into this when doing Calendar event delete (https://developers.google.com/google-apps/calendar/v3/reference/events/delete) which returns no response for successful delete.

Propose returning null for such a response.
Merge pull request #239 from hatboysam/patch-1

Update gapi-chrome-apps.js
Add desktop-capture app.

The implementation is similar to camera-capture.

TODO: capture screenshot and upload it to Google Play.
Merge pull request #238 from ds-hwang/desktop_capture

Add desktop-capture app.
Adding first draft of user agent override example
Fix up user-agent sample README.md with correct screenshot link and simpler language to describe navigation.
Fix more typos in README.md
Fix more typos in README.md
Fix more typos in README.md
Put webviews in separate partitions for better performance
[rich-notifications] Fixed HTML right angle bracket
[rich-notifications] Bumped manifest version
Update readme
Initial commit for new window api sample
Biggest change: Script injection to read <title> element for tab labels

Minor changes:
- Updated css: slightly better tabbed browser look-and-feel
- Bug fix: Select first tab during load
- Bug fix: location bar naming in Browser handlers
- Refactor tab handles to constist of <li><p>...</p><a>X</a></li>
Major change:
Implement open-in-new-tab and close-tab button correctly

Minor changes:
- CSS fix: only selected webview is visible
- Only need one webview message listener in the embedder
- Counter stored in TabList ensures unique tab names
- Order of state change + layout calls fixed in TabList.selectTab()
- Bug fix: Misspelled method(s) "detatch" -> "detach"
- Bug fix: this is that in Tab.initWebview()
- Marshall objects for message passing + use tab name in guest->embedder messages
New add-tab button
- Placed tab controls above navigation controls
- Bug fix: Remove loading class when !isLoading() (! was missing)
- Correctly decide whether or not to select new tab when new tab created
- Correctly select next or previous tab when closing selected tab
- Rename doNewWindow() to doNewTab()
- Remove debug logging (but keep warnings)
- Added keyboard shortcuts for new tab, close tab, and select tab number
- Only handle loadcommit events when they are top level
- Report '[no title]' when document title element is missing
- Preliminary description in README
- Wrap webviews in containers where popup confirmation boxes can be injected
- Abstract (collections of) popup verification boxes into their own module
- More concise context injection: (function(meaningfulCtxName) { ... }(this))
- Export browser belonging to window in preparation for instrumenting browser
  navigation
- Declare class functions as vars in modules to avoid polluting global window
  namespace