Teach file to recognize FLAC-encoded audio files.

Reference: /n/sources/patch/applied/file-knows-flac
Date: Sun Mar 14 20:19:28 CET 2010
Signed-off-by: a@9srv.net

--- /sys/src/cmd/file.c	Sun Mar 14 20:19:12 2010
+++ /sys/src/cmd/file.c	Sun Mar 14 20:19:10 2010
@@ -586,6 +586,7 @@
 	/* "pXc2 */
 	0x32630070,	0xFFFF00FF,	"pac4 audio file\n",	OCTET,
 	0xBA010000,	0xFFFFFFFF,	"mpeg system stream\n",	OCTET,
+	0x43614c66,	0xffffffff,		"FLAC audio file\n",	OCTET,
 	0x30800CC0,	0xFFFFFFFF,	"inferno .dis executable\n", OCTET,
 	0x04034B50,	0xFFFFFFFF,	"zip archive\n", "application/zip",
 	070707,		0xFFFF,		"cpio archive\n", OCTET,