Make the RND secret configurable in the DNS config file.
    Also take the named config directory, file name and log file as config parameters.
    Create the rndc file.

    Test cases to check the new config options.

Change-Id: Ia7a54134e03a20b033785a7e4a4762599b84949d
(cherry picked from commit 15b1f8887cbd69ac3068eb5a0fa9405ddccf797a)
(cherry picked from commit 6500d668eeeb9191e798aa51e17e1ed39af486a9)