org.jboss.as.clustering.controller.AttributeParsers.COLLECTION is redundant

org.jboss.as.clustering.controller.AttributeParsers.COLLECTION is currently used for 2 types of attributes:

• Lists
• Maps

The list version is unnecessary, as the default parser for the associated attribute definition parses these value correctly. The only exception is to support aliases in version 1.0 of the XSD.

The map version is very hacky, as it makes an assumption that the map value is available from the element text of the xml reader. We should use a separate parser for this type.