tmac: introduce real manual reference macro instead of overloading IR

The overloading of IR emits magic \X'...' sequences that turn into HTML manual links.
But not all such IR invocations should be manual links;
those had to be written to avoid the IR macro before.
Worse, the \X'...' ending the IR causes troff to emit only a single space after a period.

Defining a new IM macro for manual references fixes both problems.

Fixes #441.

1 files changed, 6 insertions, 6 deletions

diff --git a/man/man8/vbackup.8 b/man/man8/vbackup.8
index 26ab9178..e212435e 100644
--- a/man/man8/vbackup.8
+++ b/man/man8/vbackup.8
@@ -70,7 +70,7 @@ back up Unix file systems to Venti
 .SH DESCRIPTION
 These programs back up and restore standard
 Unix file system images stored in
-.IR venti (8).
+.IM venti (8) .
 Images stored in
 .I venti
 are named by
@@ -102,7 +102,7 @@ The argument
 .I disk
 should be a disk or disk partition device
 that would be appropriate to pass to
-.IR mount (8).
+.IM mount (8) .
 .PP
 The optional argument
 .I score
@@ -135,7 +135,7 @@ The default
 is the name returned by 
 .I sysname
 (see
-.IR getuser (3)).
+.IM getuser (3) ).
 The default
 .I mtpt
 is the place where
@@ -149,7 +149,7 @@ command.
 The default is the name returned by
 .I sysname
 (see
-.IR getuser (3)).
+.IM getuser (3) ).
 .TP
 .B -n
 No-op mode: do not write any blocks to the server
@@ -207,7 +207,7 @@ to zero unused blocks instead.
 .PP
 .I Vftp
 presents an
-.IR ftp (1)-like
+.IM ftp (1) -like
 interface to a physical or backed-up disk image.
 It is used mainly for debugging.
 Type
@@ -228,7 +228,7 @@ must be run by the user
 Because
 .I address
 is passed to the host OS kernel rather than interpreted by
-.IR dial (3),
+.IM dial (3) ,
 it must be only an IP address, not a full dial address.
 .PP
 .I Vnfs