Make use of KEK in order to securely store confidential data in the file system

Things like private keys or other confidential data that is stored in the file system shall be encrypted using the "Key Encryption Key" (KEK).

To achieve this,

• the KEK must be read out of the netx's secure info page
  This functionality is provided by a new toolbox function: PSTBNETX-75
• the KEK must be provided to the Authentication Manager component through the startup parameter: PSAUTH-173