#2132 Unify temporary file management in command.vim

test/test_sandbox_execution.vader

@@ -59,7 +59,7 @@ Execute(ALE shouldn't blow up if file cleanup happens in a sandbox):
   \ 'temporary_file_list': ['/tmp/foo'],
   \ 'temporary_directory_list': ['/tmp/bar'],
   \}
-  sandbox call ale#engine#RemoveManagedFiles(3)
+  sandbox call ale#command#RemoveManagedFiles(3)
 
   AssertEqual ['/tmp/foo'], g:ale_buffer_info[3].temporary_file_list
   AssertEqual ['/tmp/bar'], g:ale_buffer_info[3].temporary_directory_list