Disable keyboard binding for abort-display() and update manual page.

while there remove a remaining reference to non-existent xdmshell(1).
Reported by Hiltjo Posthuma, ok solene@, bentley@

app/xenodm/config/Xresources.in

@@ -1,4 +1,4 @@
-! $OpenBSD: Xresources.in,v 1.1 2017/07/26 21:14:54 matthieu Exp $
+! $OpenBSD: Xresources.in,v 1.2 2019/04/16 05:51:04 matthieu Exp $
 !
 !
 !
@@ -9,7 +9,6 @@
 
 
 xlogin*login.translations: #override \
-	Ctrl<Key>R: abort-display()\n\
 	<Key>F1: set-session-argument(failsafe) finish-field()\n\
 	<Key>Left: move-backward-character()\n\
 	<Key>Right: move-forward-character()\n\

app/xenodm/man/xenodm.man

@@ -23,7 +23,7 @@
 .\" from The Open Group.
 .\"
 .\"
-.Dd $Mdocdate: July 11 2018 $
+.Dd $Mdocdate: April 16 2019 $
 .Dt XENODM 1
 .Os __xorgversion__
 .Sh NAME
@@ -683,7 +683,6 @@ As the authentication widget reads this database before starting up,
 it usually contains parameters for that widget:
 .Bd -literal -offset Ds
 xlogin*login.translations: #override\e
-	Ctrl<Key>R: abort-display()\en\e
 	<Key>F1: set-session-argument(failsafe) finish-field()\en\e
 	<Key>Return: set-session-argument() finish-field()
 xlogin*borderWidth: 3
@@ -975,9 +974,8 @@ Terminates the server, disabling it.
 This action is not accessible in the default configuration.
 There are various reasons to stop
 .Nm
-on a system console, such as when shutting the system down, when using
+on a system console, such as when shutting the system down,
-.Xr xdmshell 1 ,
+or to generally access the console.
-to start another type of server, or to generally access the console.
 Sending
 .Nm
 a