Omit `id` from the package.json file
ModelRelation: add `hasOne` type, name/value API

Modify `ModelRelation.getValidTypes` to return a list of `{name,value}`
objects instead of no longer used `{value,humanized}` version.

Add a new relation type `hasOne`.
ModelAccessControl: remove values not implemented

Remove the values that are not implemented in loopback yet:
  Role.RELATED
  ACL.ALARM
  ACL.AUDIT
Merge pull request #86 from strongloop/hide-available-values-not-implemented-yet

Hide available values not implemented yet