Allow switch to other client by email

Hi all,

While the administrator of tickets need quickly dispatch received emails to the correct client, which has right personnel watching, I was thinking a @client syntax should satisfy this request, then I found in support_mailcmd.module there is already a case 'client' as a place holder.

Although the comment says "It's too easy at the moment to get into a state where the assignee is invalid", I think other cases have similar risks. Perhaps my scenario is simpler that I don't too much danger.

So I wrote a helper function in support.module to get client names, and tried implement this case in support_mailcmd.module, as attached.

With this,

@client = [client_name]

can switch to the client.

Please review. Thanks!

Burke