#174 Installation: *NIX installer/updater package

[Adam Franco]

The goal of this Feature Request is to create a self-contained segue package that would include shell scripts that would check for upgrades and install upgrades.

- Custom configuration, plugins, themes, etc would all have their own directories outside of the source directory.

- web-root directories would be pre-configured in a secure manner, keeping all but the index.php and static files out of web-visibility.

- A new-version directory would be set up for testing first before switch-over to the new version.

This depends on the "Installation: custom config paths" FR:
https://sourceforge.net/tracker2/?func=detail&aid=2112744&group_id=82171&atid=565237