[WFLY-1628] alias --help print nothing on jboss-cli

Command: 'alias' needs to provide some help information to the console if it is enabled, and it is enabled in wildfly console. :smile: 

Would you please review if the fix is OK?

And, since wildfly uses aesh:0.33.12, I also made another branch: https://github.com/gaol/aesh/tree/WFLY-1628-033 which contains this fix, should we make a new tag and upgrade the reference in wildfly to the new tag?