mcom: also read $VISUAL to find the editor

Closes #206.

man/mcom.1

@@ -1,4 +1,4 @@
-.Dd February 5, 2020
+.Dd April 21, 2021
 .Dt MCOM 1
 .Os
 .Sh NAME
@@ -132,8 +132,10 @@ Preview the draft, using
 .El
 .Sh ENVIRONMENT
 .Bl -tag -width Ds
-.It Ev EDITOR
+.It Ev EDITOR , Ev VISUAL
 Editor used to compose messages.
+(Default:
+.Xr vi 1 )
 .It Ev MBLAZE
 Directory containing mblaze configuration files.
 (Default:

mcom

@@ -493,7 +493,7 @@ while :; do
 		;;
 	e|edit)
 		c=
-		if ! ${EDITOR:-vi} "$draft"; then
+		if ! ${VISUAL:-${EDITOR:-vi}} "$draft"; then
 			c=d
 		else
 			if checksensible "$draft"; then