Added config parameters relevant to Hive distribution.

Also, added some sample values to the config.
Hives now connect and see each other.
Updated the .gitignore
Added cluster size and connected nodes to the Hive monitor.
Added message propagation throughout the cluster.

Once received, replies are scanned in order and first sucessful message (structured `{ok, Reply}`) is selected. If no successful messages were received, the last reply is selected. If no replies were received at all, Hive reports an error.
Added cluster config validation.

It turns out that `net_kernel` is a load of Bad Things.
Updated the documentation.
Use node name as a salt when assigning client session IDs.

Fixes #17.
Fixed Hive Cluster Manager error messages.
Propagating client messages across the cluster is useless.
Merge branch 'master' of github.com:brainly/hive into idorobots/distribution

Conflicts:
	src/hive_monitor_http_handler.erl
Merge pull request #18 from brainly/idorobots/distribution

Enables Hive to run in a cluster.