@GroupCommandDefinition tab completion improvements

A mix of @GroupCommandDefinitions and normal commands are a little hard to use with tab completion.

1.) Consider differentiating @GroupCommandDefinitions somehow? Append ":", "->", etc?

2.) Tab completion doesn't kick in, unless the group has a space after it. Example:

artificer> storedQuery<TAB>
artificer> storedQuery <TAB>
storedQuery create   storedQuery execute  storedQuery list     
storedQuery delete   storedQuery get      storedQuery update
artificer> storedQuery 

Instead, consider:

artificer> storedQuery<TAB>
storedQuery:create   storedQuery:execute  storedQuery:list     
storedQuery:delete   storedQuery:get      storedQuery:update
artificer> storedQuery:

Essentially, if you hit <TAB> and the buffer contains only one possible command (a group), immediately display all the group's commands. Currently, it "completes" the group name by adding a space and forcing you to hit tab again.
Also, consider using ":" between the group and commands, rather than a space.

3.) The listing of all possible commands is confusing, since groups and commands are not differentiated from each other. Example – here's Artificer's full tab-completion:

artificer> 
addComment       clear            echo             man              refreshMetaData  updateMetaData   
alias            connect          exit             maven            showMetaData     uploadArtifact   
archive          createArtifact   export           ontology         status           
audit            delete           getContent       property         storedQuery      
classification   disconnect       getMetaData      query            unalias

Several of those are groups (ontology, storedQuery, maven, etc.). Multiple Artificer users mentioned being confused.