AngelScript script shared library support

[zelerin]

AngelScript has many cool features, and one of them is the ability to create libraries of scripts and link them together, like with Linux .so files. Since we're starting development of scripts that are not longer demo quality, common code will come in really handy.

This implementation here would be very basic and manual (using the dump file); a future enhancement (no issue written yet) is to make use of preprocessors and regnames to dynamically find the libraries. It could be even simpler right now and auto-include a library.