Move Cursor and TokenBuffer into buffer module
diff --git a/src/expr.rs b/src/expr.rs
index 200a884..ee7aa19 100644
--- a/src/expr.rs
+++ b/src/expr.rs
@@ -804,7 +804,7 @@
     #[cfg(feature = "full")]
     use proc_macro2::TokenStream;
     use synom::Synom;
-    use cursor::Cursor;
+    use buffer::Cursor;
     #[cfg(feature = "full")]
     use parse_error;
     use synom::PResult;