Upgraded to Toggl's API v8

This project had last been updated in June 2012. The API version v6 used has been deprecated and the entire project no longer works. 

I've upgraded the project to the API v8. The key changes are:

- The API now requires specifying a Workspace to get a project list or project ID. If the user only has a single workspace (which would be most people), then these scripts will work seamlessly. If, however, the user has more than one workspace, the active workspace must be set in the settings files (just like specifying a project or client).
- Changed the code in a few places to work with the new v8 API.