Automatically saves any textarea typed in, and allows the user to view saved textarea content by clicking on a button.
As an example if you go to:
http://www.yamllint.com/ and type in that box it will be saved automatically, when you click on the FormSave icon you can view the content for any previously saved sites.
If there is a particular website that this addon does not work on (besides
addons.mozilla.org, which is disabled for security -- see
here), please mention the page with a full link to a page that does not work either in
a bug against the project at github or in your review below.
