AS7-430 Add domain controller discovery system with support for S3 discovery

Implemented domain controller discovery via S3. The master domain controller and slave host controllers can now be configured with information needed to access a file in an S3 bucket. The master domain controller writes its address and port to this file. The slaves can access this data from the S3 file when connecting to the master.

More details in https://issues.jboss.org/browse/AS7-430