merge versioning, fix bug todo

ecstore/src/disk/error.rs

@@ -260,6 +260,17 @@ pub fn os_err_to_file_err(e: io::Error) -> Error {
     }
 }
 
+pub fn is_err_file_not_found(err: &Error) -> bool {
+    if let Some(e) = err.downcast_ref::<DiskError>() {
+        match e {
+            DiskError::FileNotFound => true,
+            _ => false,
+        }
+    } else {
+        false
+    }
+}
+
 pub fn is_sys_err_no_space(e: &io::Error) -> bool {
     if let Some(no) = e.raw_os_error() {
         return no == 28;