Implement the pencil from the mockup

This implements the pencil icon as per the mockup, with a dropdown menu that allows you to edit the module or its title.

This marks a break from the FontAwesome icons. I'm not sure if I should be concerned, but if we want to emulate the mockup, this is how it needs to be.

@philschatz , in the end I did not use css for the book/module wording. While it is okay to translate the menu items on the dropdown, it is difficult to do so for title attributes on items. I also discovered bootstrap tooltips were not enabled, so I had to implement that first, and then I had to attach the tooltip to #workspace-container to make it display properly, which means it is not nested inside anything marked with the mediaType. Also, the idea that one should set the title attribute to a blank and use an ::after pseudo class to fill it in feels too clever by half and somewhat gimicky.