@ngrx/* update to v4, including required code adoptions.

[DorianGrey]

Took more effort than I previously expected, but seems to work now ...

However, some things are still left to be done:

• Since ngrx/store now supports reducers to be added from features modules: Move the state part only used in the lazy loaded chunk from the global app state to a module-local one.
• Some code cleanup - The structure got a bit messed up during this update, so it has to be cleaned. Affects the README task (see below).
• Update README on how to extend the app state properly.
• Try to enable ngrx-store-freeze - it's currently not compatible with v4, issue is already reported. Might be dispensable in case ngrx/store gets this functionality out-of-the-box (seems there are plans to do so). Atm., it'll require a hacky workaround to integrate freeze functionality due to the router snapshot in the state. -> Fixed via custom serializer in @ngrx/router-store >= 4.0.3.
• The devtools are practically unusable atm., due to the extremely large serialization of the router snapshot. See issues:
  Performance Issues with Dev Tools + Router-Store ngrx/platform#97
  Consider removing the RouterStateSnapshot from router-store state ngrx/platform#104
  Might be solved using a custom serializer, in case feat(RouterStore): Added serializer for router state snapshot ngrx/platform#188 gets merged and published. -> Fixed via custom serializer in @ngrx/router-store >= 4.0.3.
• The custom router snapshot serializer gets called twice - once with original snapshot, and once with the serialized version. Need to determine if this is a bug - reported as Custom RouterStateSerializer is called with both the original and the custom serialized version ngrx/platform#286. -> Fixed in ngrx-router-store >= 4.0.4

[GiuseppePiscopo]

Hi there. Just chiming in: there seems to be updates and new directions on how to setup a custom router state serializer, to overcome issues with store dev tools. See ngrx/platform#188 and https://github.com/ngrx/platform/blob/master/docs/router-store/api.md#custom-router-state-serializer. HTH

[DorianGrey]

Using a custom serializer seems to be the way to go, yes. However, the corresponding commit was just merged yesterday (ngrx/platform@0fc1bcc) and is not yet published in a new version. I.e. although it is already listed in the docs (which are rendered from master), this feature cannot be used yet.
Be sure that I'll implement one once this gets released.

[DorianGrey]

Serializer added, ngrx-store-freeze and dev-tools working again ... and another issue raises:
ngrx/platform#286

Merge deferred until it's determined if the current workaround is fine, or if it has to be fixed in another way.