Fix aconnect man page

Use local definitions of .EX/.EE or .DS/.DE to avoid low-level troff
requests in the page body.  There are plans to add these to groff man;
in the interim, this patch adds a compatible definition.

From: Eric S. Raymond <esr@thyrsus.com>

seq/aconnect/aconnect.1

@@ -1,5 +1,12 @@
 .TH aconnect 1 "August 31, 2000"
-.LO 1
+.de EX
+.nf
+.ft CW
+..
+.de EE
+.ft R
+.fi
+..
 .SH NAME
 aconnect \- ALSA sequencer connection manager
 
@@ -33,12 +40,16 @@ ports.
 For disconnection, use
 .B \-d
 option.
-.IP "" 4
+.sp
+.EX
 % aconnect \-d 64:0 65:0
+.EE
 .PP
 The address can be given using the client's name.
-.IP "" 4
+.sp
+.EX
 % aconnect External:0 Emu8000:1
+.EE
 .PP
 Then the port 0 of the client matching with the string "External" is
 connected to the port 1 of the client matching with the "Emu8000".
@@ -52,19 +63,15 @@ The input ports, which may become
 ports, can be listed with
 .B \-i
 option.
-.IP "" 4
+.sp
+.EX
 % aconnect \-i
-.br
 client 0: 'System' [type=kernel]
-.in +4
-0 'Timer           '
-.br
-1 'Announce        '
-.in -4
+    0 'Timer           '
+    1 'Announce        '
 client 64: 'External MIDI\-0' [type=kernel]
-.in +4
-0 'MIDI 0\-0        '
-.in -4
+    0 'MIDI 0\-0        '
+.EE
 .PP
 Similarly, to see the output ports, use
 .B \-o