Scripted the Azure packaging of Ghost and optimised the deployed configuration

Previously to package Ghost for Azure Web Gallery involved a number of manual steps that could be error prone, e.g. install SQLite3 x32/64 and packaging the zip correctly. I personally tried it a few times for the 0.4.2 and then 0.5.0 release and had difficulty. In this PR, I have created a Powershell script that packages the zip file from an official Ghost release. There is also another script to help test the package by deploying to Azure Web Site.

Also in the PR are some minor, yet important, tweaks to the default Ghost configuration that makes the Admin section of the site `/ghost*` secure out-of-the-box.

I think this PR is useful as it will make packaging Ghost for Azure Web Gallery easier, thus reducing the time required by maintainers and ensuring that everyone gets to trial/experience Ghost.