Since datasources in TorqueBox are XA enabled by default, it makes sense to prominently highlight the configuration changes that postgres users should make in order to ensure that XA works appropriately for them (i.e., setting max_prepared_transactions). This documentation should take two forms:
1. A prominent warning message - akin to HornetQ's warning message about default user/password - that appears during startup if the user attempts to connect to a postgres DS and the testSupportsXA() call fails.
2. A bit of documentation in the installation section of the docs.