Speeds up tests of AutoConfiguration.

By adding a proper unit test for testing how the AutoConfigurator configures memory mapping,
and a much smaller test than the previous integration test for making sure that auto configured values make it into the actual configuration.

Conflicts:
	community/kernel/src/main/java/org/neo4j/kernel/AutoConfigurator.java
	community/kernel/src/main/java/org/neo4j/kernel/InternalAbstractGraphDatabase.java
	community/kernel/src/main/java/org/neo4j/kernel/impl/nioneo/store/DefaultWindowPoolFactory.java
	community/kernel/src/test/java/org/neo4j/kernel/impl/core/AutoconfIT.java