v0.7.0

Secure backup added
Added new operation (B key) for secure backup.

After pressing the 'B' key:

• user is asked to select a certificate present in the appliance
  default domain
• selected certificate is used to create a secure backup of the
  appliance and save it in the directory in the temporary:
  filestore
• a new directory on the local filesystem is created
• all secure backup files are copied from the temporary filestore
  of the appliance to the local filesystem
• secure backup is deleted from the DataPower appliance (if user
  confirms deletion)

Minor changes:

• save domain implemented when using REST management interface
• tcell library update