Special reviewing models plugin

This plugin is used for special reviewing models, implemented by us for very large conferences. Currently, it includes the IJCAI/AAAI model.

The vast majority of our conferences use the standard reviewing model.

These alternative reviewing models exist to fill the niche needs of conferences whose chairs are already familiar with these alternative models. Without this experience, we recommend chairs to use our standard model.

To enables these models:

1. Select menu tabs "Administration" -> "Configure" to access the conference configuration
2. Enable the plugin "Special reviewing models"
3. Select "AAAI model" as the value of the option "Reviewing model"