Cleanup of some incorrect code comments.
Nimbus now directly parses hosts instead of requiring it to be compiled to nimbus-hosts.
nimbus-hosts and compile_hosts.py are now obsolete; removed them.
Licensing terms are now more clear. The core of Nimbus is MIT-licensed, and the extensions are Unlicensed, unless otherwise specified. This change does not affect older releases of Nimbus, which remain largely Unlicensed.