Object Store Browser Log record type handlers should be configurable via a system property

MBeans for exposing log records can be configured by:

1) calling setTypes(hash map of log record type to java class name for handling the type) on the ObjStore browser, or
2) via the manifest for the JBossTS jar

In AS7 we call setTypes with a hardcoded map from ArjunaTransactionManagerService. Since it is not feasible to update the ts jar manifest we need a more configurable way of defining the types (this is particularly relevant for exposing SubordinateAtomicAction created in support of JBTM-895.