Split the framework into different modules and don't require the plugin to be installed

[leonardo-dgs]

In this way would be easy to use it in open source projects without making the jar huge without unneeded files.
It shouldn't require to install any plugin, because a "central" framework on which all plugins depend could be fine for a private project for a server, but it's a bad idea for open source and public plugins.

It's better to have different libraries, for each purpose, decoupled from each other, so if you don't like one, you can just use another library.
With monolithic frameworks you are either obliged to use all the features of it, or to use another library for that particular purpose, making the jar file even bigger.

For example I was just watching for a simple localization library for some my open source projects, and I don't want to add a "Core" plugin as dependency, only for that feature.