Merge branch 'master' into issue_459_371

Author: atollk

CHANGELOG.md

@@ -12,12 +12,15 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 - To `fs.walk.Walker`, added parameters `filter_glob` and `exclude_glob`.
   Closes [#459](https://github.com/PyFilesystem/pyfilesystem2/issues/459).
+- Added `fs.copy.copy_file_if`, `fs.copy.copy_dir_if`, and `fs.copy.copy_fs_if`. 
+  Closes [#458](https://github.com/PyFilesystem/pyfilesystem2/issues/458).
 
 ### Fixed
 
 - Elaborated documentation of `filter_dirs` and `exclude_dirs` in `fs.walk.Walker`.
   Closes [#371](https://github.com/PyFilesystem/pyfilesystem2/issues/371).
-  
+- Fixed performance bugs in `fs.copy.copy_dir_if_newer`. Test cases were adapted to catch those bugs in the future.
+
 
 ## [2.4.13] - 2021-03-27