ls: moved generic URI utilities to uri.c

"ls" is a bad name for a library which parses URIs.  We'll move the
rest of the "ls" library later.

src/queue_save.c

@@ -19,7 +19,7 @@
 #include "queue_save.h"
 #include "queue.h"
 #include "song.h"
-#include "ls.h"
+#include "uri.h"
 #include "database.h"
 
 #include <stdlib.h>