Enable redundant domains with multiple daemon connections

Enable redundant domains with multiple daemon connections.

This a change to how domains are handled in OpenHPI. Currenly, on daemon handles all domains. Domains are defined in terms of entity path patterns. Also, one client can only connect to one daemon.

This is problematic when thinking about peer domains, whose purpose is to bring a sense of redundancy to HPI users between domains. Plus, the remotability aspect is limited since the client could only connect to one domains and is tied to the inherent remote interfaces of the hardware to manage.

This was discussed last year in the mailing list, and I presented a solution that will convert a daemon into a single domain. In addition, the client will be able to connect to multiple daemons. So the client, in order to connect to multiple domains, will have to know about them through a client configuration file. It will then connect to the specified domain through a connection to the daemon corresponding to that domain.
Thus, the peer domain concept comes alive allowing for a truer sense of redundancy. This is because Peer domains can be running in different machines now.