[Reviewer: Matt] Homestead as HSS development

Fixes issues: metaswitch/crest#164, metaswitch/crest#162, metaswitch/crest#47. In conjunction with Phil's change of moving monit to upstart metaswitch/crest#148 should also be fixed. Also, included are ENTs for improved craft/syslog logs. Plus, command line tools for provisioning subscribers in the absence of Ellis.
We should log how much we're overloaded.  Maybe we should log on entering/exiting overload (rather than just on each rejected request).