Dispatch Projects Update

***Change Log:***

**gwtp-dispatch-rest**
- Replaced Piriti by [gwt-jackson](https://github.com/nmorel/gwt-jackson)
- Removed missing jax-rs annotation from the compile report
- Added extension points and interfaces
- Moved some code from the `RestDispatch` implementation to `RestDispatchCall`

**gwtp-dispatch-client**
- Renamed artifact to *gwtp-dispatch-rpc-client*
- Moved classes to `com.gwtplatform.dispatch.rpc.client.*`
- The old classes are still there but are deprecated. If you wish to stay up to date and prevent future migration issues, make sure you use the classes available in `com.gwtplatform.dispatch.rpc.client.*`
- Added extension points and interfaces
- Moved some code from the `DispatchAsync` implementation to `RpcDispatchExecuteCall` and `RpcDispatchUndoCall`. They have the same extensions points `DispatchAsync` previously had

**gwtp-dispatch-server**
- Renamed artifact to *gwtp-dispatch-rpc-server*
- Moved classes to `com.gwtplatform.dispatch.rpc.server.*`
- The old classes are still there but are deprecated. If you wish to stay up to date and prevent future migration issues, make sure you use the classes available in `com.gwtplatform.dispatch.rpc.server.*`

**gwtp-dispatch-server-guice**
- Renamed artifact to *gwtp-dispatch-rpc-server-guice*
- Moved classes to `com.gwtplatform.dispatch.rpc.server.guice.*`
- The old classes are still there but are deprecated. If you wish to stay up to date and prevent future migration issues, make sure you use the classes available in `com.gwtplatform.dispatch.rpc.server.guice.*`

**gwtp-dispatch-server-spring**
- Renamed artifact to *gwtp-dispatch-rpc-server-spring*
- Moved classes to `com.gwtplatform.dispatch.rpc.server.spring.*`
- The old classes are still there but are deprecated. If you wish to stay up to date and prevent future migration issues, make sure you use the classes available in `com.gwtplatform.dispatch.rpc.server.spring.*`

**gwtp-dispatch-shared**
- Renamed artifact to *gwtp-dispatch-rpc-shared*
- Moved classes to `com.gwtplatform.dispatch.rpc.shared.*`
- The old classes are still there but are deprecated. If you wish to stay up to date and prevent future migration issues, make sure you use the classes available in `com.gwtplatform.dispatch.rpc.shared.*`

**Additions**
- Created 2 new artifacts *gwtp-dispatch-common-shared* and *gwtp-dispatch-common-client*. They contain code (ie: `DispatchCall` abstraction) shared by both the REST and RPC dispatch projects.