I had a quick look at the errors and this is a mistake by the creator of this module, the LdapServer module is irrelevant to this project and even if you imported it, the module still wouldn't actually function (though you might be able to compile)
The encryption error is easy to fix though, the EncryptPassword and DecryptPassword action both have a method that takes a key string (should be a 16 bit key) and a string to encrypt/decrypt as a parameter. These actions are actually made by me and copied into this project, for the original project and how it should work (including proper documentation) you can have a look at the Exchange client appstore module.