don't set values for verbose and syslog by default

Setting the values in the setup file by default makes it annoyingly hard to
override them at the command line (since setup files override the command
line).

Both default to off if no value is set.

IkiWiki.pm

@@ -172,14 +172,14 @@ sub getsetup () { #{{{
 	},
 	verbose => {
 		type => "boolean",
-		default => 0,
+		example => 1,
 		description => "display verbose messages when building?",
 		safe => 1,
 		rebuild => 0,
 	},
 	syslog => {
 		type => "boolean",
-		default => 0,
+		example => 1,
 		description => "log to syslog?",
 		safe => 1,
 		rebuild => 0,