Add an option to send statistics.
Add Chrome Platform Analytics library as a submodule.
Send the AppView to Analytics.
Send some settings statistics to Analytics.
Merge branch 'master' of github.com:GoogleChrome/text-app into analytics
Fix a string description, add separate property for Text Dev.
Use chrome.runtime.id instead of name to select Analytics property.
Merge pull request #213 from GoogleChrome/analytics

Send usage statistics to Google Analytics.
Close #107