Sort out the C++ side of fgdlib so we know wtf is going on, organize our C# interop nicer because of it. * Split fgd file parsing away so we have more ownership of GameData and it's way less confusing. * Classes, variables, globals are named properly e.g pGD -> g_pGameData (it got very confusing when pGD is a parameter name everywhere too) * Document what GameData is & how we use it in s&box. * Sort out code stink, unnecessary long compile times and remove some headers that haven't been used in the past couple of decades. Add "point" and "solid" tags to applicable managed gamedata classes, Hammer likes to use these over the type for some things Don't mix AssemblyLoadContexts, I've one this part all pretty wank need to revisit this bit later. Implement Inputs and Outputs, the parameter types make more sense now and entity parameters should work now too. Remove map entity related stuff we've already ported to our tools from FGDWriter