Add catv (separate applet instead of cat -v). Also cleanup cat.c comments,

the following of which (from cat.c) belongs in svn history instead of the
source code:

/* Mar 16, 2003      Manuel Novoa III   (mjn3@codepoet.org)
 *
 * This is a new implementation of 'cat' which aims to be SUSv3 compliant.
 *
 * Changes from the previous implementation include:
 * 1) Multiple '-' args are accepted as required by SUSv3.  The previous
 *    implementation would close stdin and segfault on a subsequent '-'.
 * 2) The '-u' options is required by SUSv3.  Note that the specified
 *    behavior for '-u' is done by default, so all we need do is accept
 *    the option.
 */

include/usage.h

@@ -136,6 +136,13 @@
 	"$ cat /proc/uptime\n" \
 	"110716.72 17.67"
 
+#define catv_trivial_usage \
+	"[-etv] [FILE]..."
+#define catv_full_usage \
+	"Display nonprinting characters as ^x or M-x.\n\n"\
+	"\t-e\tEnd each line with $\n" \
+	"\t-t\tShow tabs as ^I\n" \
+	"\t-v\tDon't use ^x or M-x escapes."
 #define chattr_trivial_usage \
 	"[-R] [-+=AacDdijsStTu] [-v version] files..."
 #define chattr_full_usage \