Add support for 'noheader' option

This option can be used to disable the standard cgit page header, which
might be useful in combination with the 'embedded' option.

Suggested-by: Mark Constable <markc@renta.net>
Signed-off-by: Lars Hjemli <hjemli@gmail.com>
diff --git a/cgit.c b/cgit.c
index 2aef44d..38f0fdd 100644
--- a/cgit.c
+++ b/cgit.c
@@ -49,6 +49,8 @@
 			ctx.cfg.virtual_root = "";
 	} else if (!strcmp(name, "nocache"))
 		ctx.cfg.nocache = atoi(value);
+	else if (!strcmp(name, "noheader"))
+		ctx.cfg.noheader = atoi(value);
 	else if (!strcmp(name, "snapshots"))
 		ctx.cfg.snapshots = cgit_parse_snapshots_mask(value);
 	else if (!strcmp(name, "enable-index-links"))