Config server with settings

Added setting interface (ServerSettings and ServerInternalSettings) for server to access its configuration properties.

Enabled to obtain a server property with Config.get + property settings. Replaced the previous Apache Configuration + constant string property-accessing-pattern. 
I'd love a test that did:

    // Given
    server = serverWithoutDBLocationSpecified

   // When
   server.start()

   // Then 
   assertServerStartedAndPutDatabaseInExpectedLocation()