Add CLR management features

[C-Sto]

trafficstars

The aim of this PR is to provide the ability to:

• easily create and unload named appdomains
• stop the runtime on demand
• be able to list loaded assemblies
• be able to get a reference to an assembly within the appdomain without needing to manually keep track of them

Did my best to try and keep to the Go sanctioned use of unsafe.Pointer, and tried to stick to the existing code style, but took some creative freedom here and there.

[binarytrails]

@C-Sto amazing work! thank you