Major fixes:

- ChunkIterator is now bidirectional
- LineIterator is now also bidirectional
- Undo/redo history operations
- Replace operation
- Range based api functions
- And more minor bug fixes

include/vase/shard.h

@@ -2,6 +2,7 @@
 
 #include "buffer/buffer.h"
 #include "buffer/original.h"
+#include "constants.h"
 #include "pch.h"
 #include "utils/utils.h"