Replace AutoSave component with modal form

[srallen]

One of Brian's suggestions before he left: replace the AutoSave component in the project builder where appropriate with a modal form with an explicit save and cancel button and a place in the UI for error messaging. This would greatly improve the UI/UX for project builder. The field guide editor currently does this and can be looked as an example for implementation.

[mschwamb]

related to #581

[jelliotartz]

Closing as this has not received comments or action for over a year.