Add typedef support to AngelScript

[msmorgan]

Other language features that could be useful:

• abstract
• Shared mixin classes
• Treat imported functions as shared

[codecat]

This is something you'll want to suggest on the Angelscript forum: https://www.gamedev.net/forums/forum/34-angelcode/

[msmorgan]

But these are on their doc site as language features?

Edit: I see typedefs aren't as useful as I hoped since they can only represent primitives.

[msmorgan]

To add to this list: weakref support