New journal event "command"

Redundant information.  Allows making sense of input without context.
The redundancy could help making a journal replay tool more robust.

src/lib/subs/journal.c

@@ -27,7 +27,7 @@
  *  journal.c: Log a journal of events to a file
  *
  *  Known contributors to this file:
- *     Markus Armbruster, 2004-2008
+ *     Markus Armbruster, 2004-2011
  *     Ron Koenderink, 2008
  */
 
@@ -43,6 +43,7 @@
  *     prng NAME SEED
  *     login CNUM HOSTADDR USER
  *     logout CNUM
+ *     command NAME
  *     input INPUT
  *     update ETU
  */
@@ -172,6 +173,13 @@ journal_input(char *input)
     journal_entry("input %s", input);
 }
 
+void
+journal_command(char *cmd)
+{
+    char *eptr = strchr(cmd, ' ');
+    journal_entry("command %.*s", eptr ? (int)(eptr - cmd) : -1, cmd);
+}
+
 void
 journal_update(int etu)
 {