imp(Completions): completions now continue completing even after first completion

Prior to this change, completions only allowed one completion per command, this change allows as
many as required. The one downside to this change is the completion engine isn't smart enough to
determine which options are no longer legal after certain options have been applied.

src/completions.rs

@@ -78,6 +78,8 @@ impl<'a, 'b> ComplGen<'a, 'b> {
                     COMPREPLY=()
                     ;;
             esac
+            COMPREPLY=( $(compgen -W \"${{opts}}\" -- ${{cur}}) )
+            return 0
             ;;
         {subcmd_details}
     esac
@@ -133,6 +135,8 @@ complete -F _{name} {name}
                     COMPREPLY=()
                     ;;
             esac
+            COMPREPLY=( $(compgen -W \"${{opts}}\" -- ${{cur}}) )
+            return 0
             ;;",
                 subcmd_dets,
                 subcmd=sc.replace("-", "_"),