Save/Export Feature

After a bit of deliberation in some other issue threads, this export/save system is fully compatible and tested in IE10, Chrome, Safari, and Firefox. It is strictly JS with a few plugins to help with the facilitation of saving files. 

Currently the save feature exports in HTML, Markdown, and Plain Text though many more options can be added as they are needed. The code also makes it easy for the user to simply copy and paste their text in their preferred format, with the usual ctrl (cmd) + c.

Right now the icon is an S though that can easily be swapped out for something else at any other time. Any other questions, feel free to ask. Thanks!