Server script to download the latest installer

As promised, I talked with enumag about the script and he sent it to me earlier today.

You can access it at http://07th-mod.com/installer.php

By default, it will guess the user platform and get the latest stable release. You can force it to go through manually using: ``http://07th-mod.com/installer.php?system=win|mac|linux&branch=pre|stable``

Example: http://07th-mod.com/installer.php?system=linux&branch=stable

Beware that using ``branch=pre`` will only work if the most recent release is marked as a pre-release. If the most recent is a stable release, it will get the stable instead of the pre-release.

Right now the guessing part doesn't work, but I believe it is because of the current changes ongoing at the releases page. Earlier today it was working fine, so it might fix itself soon enough.

El script está alojado en http://07th-mod.com/installer.php e interactúa con los lanzamientos de GitHub. Comience examinando la lógica existente del lado del servidor para la detección de plataformas y la obtención de lanzamientos. Comprenda cómo determina las ramas 'stable' vs. 'pre' y se integra con la página de lanzamientos del proyecto. Pruebe el endpoint con diferentes parámetros de consulta para verificar el comportamiento actual e identificar el problema de adivinación.

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