108: Major Subnet Refactor

I realised that in order to have proper encapsulation of the applications, one
must have per app subnet. Hence removed the automatic creation of a single
private subnet.

Each application (be it a DB or a web app) will create its own private subnet
and append rules to the other public subnet and its Bastion and NAT subnets.
This will allow for better security in depth.

:pear: @3000 Although he doesnt know about this yet.
108: Stack update now works fine.
108: NAT'ing like I should have.

So previously I thought that just by pointing a vanilla EC2 instance as a NAT
instance for the VPC, all the NAT'ing would be taken care of.

Alas, was I ever so young.
108: Allow the NAT to be a NAT

:pear: @3000
108: Write user data like user data.

AKA Horribly

:pear: @3000
108: Fixed typo
Merge pull request #5 from popanything/remove-automatic-private-subnet

Remove automatic private subnet