Document better the rdbname parameter

[kadler]

We should document that this parameter specifies the name of a Relational Database entry (RDB). Any database listed in WRKRDBDIRE on the host specified can be connected to. While it's probably more advisable to connect to remote database directly by specifying a different host instead of using DDM through the local system, one way RDB entries are used is for ASPs.

We should document 3 different examples:

• *LOCAL / empty string: the local system database
• ASP name
• Remote system name, with the caveat that you should probably connect directly instead