Easy file_to_id()

file_to_id() can stat the filepath to find the inode number (aka the
song id).  This is much easier than doing a bunch of lookups.  What I
really want to do eventually is get rid of file_to_id()...

libsaria/collection/library.py

@@ -75,14 +75,7 @@ def walk():
 		yield tag[3]
 
 def file_to_id(file):
-	global fs_tree
-	stripped = file.strip(libsaria.path.sep)
-	split    = stripped.split(libsaria.path.sep)
-
-	res = fs_tree.walk_path(split)
-	if res == False:
-		return None
-	return res[0]
+	return os.stat(file).st_ino
 
 def get_attrs(id, *attrs):
 	res = []