INT-2998: Channel Adapters' Lifecycle Refactoring

* Add XSD attributeGroup `smartLifeCycleAttributeGroup`
* Use it for all adapters tags
* Refactoring `AbstractChannelAdapterParser` hierarchy
* Refactoring some `MessageHandler`'s that should not have `autoStartup` & `phase`.
    It is the responsibility of `AbstrctEndpoint`
* Polishing some tests according new logic

JIRA: https://jira.springsource.org/browse/INT-2998

INT-2998: Polishing

Polishing

 - Reformat schemas where indentation changed
 - Add SLC to the UDP inbound adapter