acl PlainPermissionManager key  file paths may be inconsistent

The ACL configuration file (folder) path is maintained in ACL PlainPermissionManager, which is currently simply recorded in String and referenced in several Maps. The path String needs to be optimized to avoid "~/path1", "~//path1", "~/path1/." being treated as different paths.

Generally, fixing an issue goes through the following steps:
1. add fixed code
2. add unit test 