Feat/notify from outside

[petercrona]

Adds notifier functions, functions that do not modify the cache, but can be used to trigger invalidation.

_notifyCreate
_notifyRead
_notifyUpdate
_notifyDelete

which will invalidate based on what is specified in an entity config. For eg. calling _notifyRead in { invalidates: ['user'], invalidatesOn: ['READ'], api: apiFns } would invalidate "user".

Usage: api.user._notifyCreate() // as if a normal create operation was called, but cache is untouched.

This allows the users to model their invalidation logic in Ladda and use it before they use Ladda for all API calls. A possible next step would be to allow the users to override the notify functions with their own implementations, that can also be configured on an API function level (eg. invalidate another api function). This might not be necessary though, since most of the time NO_OPERATION can be used for this.

[coveralls]

Coverage decreased (-0.6%) to 98.638% when pulling 476fa94 on feat/notify-from-outside into 1f579db on master.

[coveralls]

Coverage decreased (-0.3%) to 98.938% when pulling 3c8b0c5 on feat/notify-from-outside into 1f579db on master.

[coveralls]

Coverage decreased (-0.3%) to 98.938% when pulling cda69c9 on feat/notify-from-outside into 1f579db on master.

[coveralls]

Coverage decreased (-0.3%) to 98.938% when pulling cda69c9 on feat/notify-from-outside into 1f579db on master.

[coveralls]

Coverage increased (+0.2%) to 99.388% when pulling 2b56bd1 on feat/notify-from-outside into 1f579db on master.