mc - By the time processChain method is called, we already have the sorted chain,
and now we have the direction, MEP, MessageContext, and if a response is expected. We should
be able to handle everything from here, no pun intended.
Two things a user of processChain should check when the method completes:
1. Has the MessageContext.MESSAGE_OUTBOUND_PROPERTY changed, indicating reversal of message direction
2. Has the message been converted to a fault message? (indicated by a flag in the message)
Converts the Exception into an XML Fault Message that is stored on the MEPContext.
Note that if the forceConversion flag is true, this conversion will always occur.
If the checkMsg flag is true, this conversion only occurs if the Message is not already
a Fault (per 9,3,2.1 of the JAX-WS specification)
mepCtx - MEPContext
e - Exception
protocol - Protocol
forceConversion - If true, the Exception is always converted to a Message