more conditions for hosts entry

on mnodes there is no eth0 and the node[:interface_mappings] do not
reflect this. so need to handle that.  Also added a handle for a case
where there is no ip. Just use localhost ip 127.0.0.1
use node[:hostname]
break the host entry up to avoid line limits

also caught a bug where we werent assigning
 fix FC019 errors
raise instead of trying to be smart
Merge pull request #34 from cloudware-cookbooks/host_crap

Fixes Mnode, and better handling of non interface_map ints