Merge pull request #79 from EricWittmann/master

Documentation for ClientExceptionMapper
Undoing backoff logic in ClientMessageBusImpl.init() because it was interfering with a weld-integration test

Note that the original TransportHandler backoff is still in place, as is the test that protects it.
Fixed bug that caused intermittent failures in EventObserverIntegrationTest

The problem was that we relied on a runtime check (canMarshall) to decided whether or not to advertise a CDI event type to the server. However, this check will always fail for abstract types as canMarshall will return false. So whenever the bus reconnected we failed to advertise observable interfaces and abstract types to the server. Since we already collect all local-only event types on startup this check can now be removed.
Change forge-errai link to v2.0.0.Beta1 tag.
Set width of getting started screenshots to 650.
Lots of doc improvements.

Linked to Errai Forge Addon tag (Beta1).
Add plugin tips and general editting up to Marshalling section.
More doc improvments.

Add plugin tips and manual setup notes up to errai navigation.
Move all setup/configuration instructions in those sections to single
location.
Finish restructuring of docs up to Configuration section.
Reorganize Configuration section of docs.
Commit change to docbook reference.xml