Bug 1005426 - Better CLI Parsing and Error reporting

* Unified behavior for CLI script args and "login" command args
* Fixed "login" command:
** support host definition without port definition
** output defaults for host and port
** command syntax message
** show meaningful error messages:
*** for port number format
*** for unsupported transport
*** for exceptions (use exception cause message instead of meaningless JBoss Remoting exception message)

Also, some code cleanup

(cherry picked from commit 5fec5167ff76c9081203b538db9098ad47765fe2)
Signed-off-by: Jirka Kremser <jkremser@redhat.com>

Conflicts:
	modules/enterprise/remoting/cli/src/main/java/org/rhq/enterprise/client/commands/LoginCommand.java