Add Rundown tab to plans

[jzongker]

If "includeRundown" is selected on a plan, include a new Rundowns tab on it. This contains the order of items in a service.

The user should be able to add headings (Welcome, Worship, Sermon), then add either plain text items to those such as 5 minute countdown, or add songs from their library.

Let the user drag/drop items to set the order.

When adding a song, prompt them for the key.

Include a duration for each item (except headers) and sum up the value to produce the total service duration and duration for each header.

Each item can have notes.