reorganized message types

Make Control messages be out-of-band async messages, without a pointer
to a previous message.

And then followed the type change through the code for hours..

This commit was sponsored by Nick Daly on Patreon.

1 files changed, 1 insertions, 0 deletions

diff --git a/CmdLine.hs b/CmdLine.hs
index 2cfea7a..cf9e2b7 100644
--- a/CmdLine.hs
+++ b/CmdLine.hs
@@ -1,5 +1,6 @@
 module CmdLine where
 
+import Data.Monoid
 import Options.Applicative
 
 data CmdLine = CmdLine