Bug 1139684 - eap cli script does not get correct result code for eap domain server on windows

This is due to "WFLY-3578 jboss-cli.bat always exits with return code 0 even after a cli failure"
https://issues.jboss.org/browse/WFLY-3578

Added jboss-cli-wrapper.bat
Calling "cmd /c jboss-cli.bat" will always return 0 even if an error occurs in the CLI
Calling it through the wrapper solves the issue

Side work:
* fix standalone and domain startup: start script prefix, if set, was not added
* when an error occurs, execute command and execute script operations now copy process output into the operation result instead of the error message
* some code cleanup (avoid possible NPE)