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, 5 deletions

diff --git a/man/man4/vacfs.4 b/man/man4/vacfs.4
index 143e782b..0c92ff60 100644
--- a/man/man4/vacfs.4
+++ b/man/man4/vacfs.4
@@ -26,7 +26,7 @@ vacfs \- a Venti-based file system
 .SH DESCRIPTION
 .I Vacfs
 interprets the file system created by
-.IR vac (1)
+.IM vac (1)
 so that it can be mounted into a Plan 9 file hierarchy.
 The data for the file system is stored on a Venti server
 with a root fingerprint specified in
@@ -37,7 +37,7 @@ clients are not authenticated, and groups are assumed to
 contain a single member with the same name.
 These restrictions should eventually be removed.
 .PP
-Options to 
+Options to
 .I vacfs
 are:
 .TP
@@ -49,7 +49,7 @@ The network address of the Venti server.
 The default is taken from the environment variable
 .BR venti .
 If this variable does not exist, then the default is the
-metaname 
+metaname
 .BR $venti .
 .\" which can be configured via
 .\" .IR ndb (6).
@@ -81,5 +81,6 @@ The amount of memory, in bytes, allocated to the block cache. The default is 16M
 .SH SOURCE
 .B \*9/src/cmd/vac
 .SH "SEE ALSO"
-.IR vac (1),
-Plan 9's \fIventi\fR(8)
+.IM vac (1) ,
+Plan 9's
+.IR venti (8)