Fixup skinny CLI completion.

Auto complete for skinny debug allows multiple options and negation, also add 
debug all option. Usage example: 'skinny debug all -packets' (each can be 
autocompleted including -packet).

Change show device to use device name. Remove the duplicate ast_strdup's from 
place calling device complete return immediately from complete devicename and 
complete linename so that multiple options are displayed on the CLI if more 
than one option available.

Review: https://reviewboard.asterisk.org/r/2333/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@381717 65c4cc65-6c06-0410-ace0-fbb531ad65f3