Parameters cleanup

Mark optional parts as such and briefly document components. Sync with
the man page. The address part for options -a and -b is technically
optional too.

bin/varnishd/mgt/mgt_main.c

@@ -141,11 +141,14 @@ usage(void)
 #define FMT "    %-28s # %s\n"
 
 	fprintf(stderr, "usage: varnishd [options]\n");
-	fprintf(stderr, FMT, "-a address:port,proto",
+	fprintf(stderr, FMT, "-a address[:port][,proto]",
 	    "HTTP listen address and port (default: *:80)");
-	fprintf(stderr, FMT, "-b address:port", "backend address and port");
-	fprintf(stderr, FMT, "", "   -b <hostname_or_IP>");
-	fprintf(stderr, FMT, "", "   -b '<hostname_or_IP>:<port_or_service>'");
+	fprintf(stderr, FMT, "", "  address: defaults to loopback");
+	fprintf(stderr, FMT, "", "  port: port or service (default: 80)");
+	fprintf(stderr, FMT, "", "  proto: HTTP/1 (default), PROXY");
+	fprintf(stderr, FMT, "-b address[:port]", "backend address and port");
+	fprintf(stderr, FMT, "", "  address: hostname or IP");
+	fprintf(stderr, FMT, "", "  port: port or service (default: 80)");
 	fprintf(stderr, FMT, "-C", "print VCL code compiled to C language");
 	fprintf(stderr, FMT, "-d", "debug");
 	fprintf(stderr, FMT, "-F", "Run in foreground");
@@ -162,7 +165,7 @@ usage(void)
 #endif
 	fprintf(stderr, FMT, "", "  -j unix[,user=<user>][,ccgroup=<group>]");
 	fprintf(stderr, FMT, "", "  -j none");
-	fprintf(stderr, FMT, "-l vsl,vsm", "Size of shared memory file");
+	fprintf(stderr, FMT, "-l vsl[,vsm]", "Size of shared memory file");
 	fprintf(stderr, FMT, "", "  vsl: space for VSL records [80m]");
 	fprintf(stderr, FMT, "", "  vsm: space for stats counters [1m]");
 	fprintf(stderr, FMT, "-M address:port", "Reverse CLI destination");

doc/sphinx/reference/varnishd.rst

@@ -15,7 +15,7 @@ HTTP accelerator daemon
 SYNOPSIS
 ========
 
-varnishd [-a address[:port][,PROTO]] [-b host[:port]] [-C] [-d] [-F] [-f config] [-h type[,options]] [-i identity] [-j jail[,jailoptions]] [-l shl[,free]] [-M address:port] [-n name] [-P file] [-p param=value] [-r param[,param...]] [-S secret-file] [-s [name=]kind[,options]] [-T address[:port]] [-t TTL] [-V] [-W waiter]
+varnishd [-a address[:port][,PROTO]] [-b host[:port]] [-C] [-d] [-F] [-f config] [-h type[,options]] [-i identity] [-j jail[,jailoptions]] [-l vsl[,vsm]] [-M address:port] [-n name] [-P file] [-p param=value] [-r param[,param...]] [-S secret-file] [-s [name=]kind[,options]] [-T address[:port]] [-t TTL] [-V] [-W waiter]
 
 DESCRIPTION
 ===========