clean up CNAME and A records
Merge branch 'sg_refactor' of github.com:jl2501/awsheet into jl2501-sg_refactor
add ipaddress to requirements.txt
Merge branch 'sg_refactor'

Adding in SecurityGroupHelper orchestration and at exit reconvergence of problematic rules.
Basically, rules that refer to other security groups that aren't declared yet, and thus
don't exist in Amazon yet, we wait to converge those ones until after they have declared
themselves at which point the script exits and calls the functions registered to run at
script exit time which will reexamine the rules that failed, rule by rule and try to converge
again.
The assumption is that by now all the security groups have been declared, so it better be able
to find them by the end if they should be referring to each other by a resource reference key.
fixed many bugs

SecurityGroupHelper module has been fixed so look up rules and key them
correctly

added a utility function to heet core to check if something looks like a
correctly formatted resource reference