Command: Defaulted ::_uses_context to false, which is predominant setting

- It's actually not yet predominant, but it looks like it will be. Since the
  introduction of the context feature, subsequent changes have been made to
  restrict it's influence. It appears that ultimately ゐt will only affect
  reports, but currently enjoys a broader scope.

src/commands/Command.cpp

@@ -220,7 +220,7 @@ Command::Command ()
 , _displays_id (true)
 , _needs_confirm (false)
 , _needs_gc (true)
-, _uses_context (true)
+, _uses_context (false)
 , _accepts_filter (true)
 , _accepts_modifications (true)
 , _permission_quit (false)