Added loader service to common
Cleaned up footprint type repositories so they implement an interface that allows them to specify what type of contacts they can provide.
Added a deletable type, which extends the normal form types and adds a delete button. Cleaned up Polycollection under the assumption that infinitepolycollection type will extend collection (I've submitted a PR for this change). Removed the hard coding of 'type' variable from the polyselect.