The OPAL SOS framework tries to meet the following objectives:
* reduce the cascading error messages and the amount of code needed to print an error message.
* build and aggregate stacks of encountered errors and associate related individual errors with each other.
* allow registration of custom callbacks to intercept error events.
For more information, refer to
https://svn.open-mpi.org/trac/ompi/wiki/ErrorMessages
This commit was SVN r23158.
