New posting workflow (Finish button) + options in NavBar

This PR contains an updated posting workflow that helps the user save, update, and publish posts & pages to their WP blog by presenting them with a single "Finish" button in the navbar. By default, new pages and posts now have draft status. The options button was also moved to the upper right of the navbar so it is more accessible in general:

![toolbar](https://f.cloud.github.com/assets/154014/2479764/f141a2ac-b0a1-11e3-99d5-07ea5328a36f.png)

The UIActionSheet options will differ depending on the current status, if it is a page or a post, if the post was previously saved to the server, etc. Some examples:

![new_post](https://f.cloud.github.com/assets/154014/2479775/700ac758-b0a2-11e3-9c86-cb0646dd768f.png)
![published_update](https://f.cloud.github.com/assets/154014/2479776/79a9c9b2-b0a2-11e3-8e2b-73194375cf76.png)
![published_page_update](https://f.cloud.github.com/assets/154014/2479778/81c8af82-b0a2-11e3-97e5-006646944745.png)