Limit iD presets via a URL parameter

[quincylvania]

Sometimes tasking managers that link to iD want to limit what presets iD allows by default. We should make this easy via a URL parameter.

While iD currently supports links to MapRules files, this mechanism can be complicated and overkill for many uses. MapRules allows complete preset customization and custom validation rules based on tags. This feature is just about limiting presets.

For example, the following query parameter could suffice to only allow adding buildings and residential roads via their preset IDs:

presets=building,highway/residential

One caveat to keep in mind is that users could accidentally follow one of these links outside of a task and not have full access to iD's presets.