Find FDOMessage.cat without having to set NLSPATH

[tomfukushima]

On Linux, FDO needs the NLSPATH environment variable to be set before it can find the FDOMessage.cat file for messages. If this variable is not set messages such as CLNT_4_PROVIDERNOTREGISTERED are produced; if it is set then the message “FDO Provider Not Registered” is returned as the exception message.

This enhancement is to change the behavior so that if NLSPATH is not set, then FDO would look in <FDO install directory>/nls for the FDOMessage.cat file.

Hopefully, this is possible. Also, I'm not sure if the same problem exists on Windows, but it doesn't seem to (so perhaps this is actually a defect).

[tomfukushima]

#5641