Commands aliases do not display syntax help/tab complete correctly

Commands aliases do not display their syntax until you've started typing, and do not tab complete even then. They also display the name of the main command instead of the alias in the arguments (when those are displayed).

Affected commands

• /tell (alias of /msg)

• /w (alias of /msg)

• /xp (alias of /experience)

• /tp (alias of /teleport)

To reproduce

• Type /xp. Observe that there is no syntax help, while /experience does display them.

• Type /xp a, and then press tab. Observe that tab completion does not occur, while it does work for /experience a.

• Type /xp a and look at the syntax help. Observe that it references /experience, not /xp.