Provide more meaningful error message in XdbDbStop and ShutdownXDB

Only e.getMessage() is shown when error happens.

-bash-3.2$ gs-shutdown.sh -u admi -p sec
ERROR: com/edb/gridsql/parser/core/syntaxtree/ShutdownXDB
Parameters: <connect> [-f]
where <connect> is -j jdbc:edb://<host>:<port>/xdbadmin?user=<username>&password=<password>
or [-h <host>] [-s <port>] -u <user> [-p <password>]
-h <host> : Host name or IP address where XDBServer is running. Default is localhost
-s <port> : XDBServer's port. Default is 6453
-u <user>, -p <password> : Login to the server
-f : Force mode. Try and shutdown server even if databases are online.

We have been using the same command.
The stack trace should be displayed and possibly omitting usage text when error happens.

In most cases error is either invalid command parameters or server message which is usually meaningful.
Stacktrace would say nothing to database user, only developers may be interested.
If you are developer you can take advantage of open source and modify it for you as you want.