"collections" endpoint

[dkastl]

After being able to also update field notes (see #28 ) the missing feature is access on SMASH to issues that were created by others and are not available on the phone.

"Projects" in SMASH seem to be the best place to manage collections of field notes (issues), however SMASH projects are different to projects in Redmine.

A user probably doesn't want to sync all issues of a Redmine project to SMASH.That's why I started thinking of SMASH's project as "surveys", "workspaces" ... or "collections".

They are basically a collection of field notes and it's not necessary to assume a user follows a certain schema to organize issues within projects.Queries (=saved filter statements) in Redmine are probably a rarely used functionality.
But they could actually solve exactly that: allow the users to create a collection of issues.

It might be easier to introduce a new endpoint queries under the name collections. That way the API can serve a better format and the plugin can take control over the API.

Suggested API endpoint:

GET /smash/collections.json

Which would return a list of available queries of the user.