* explicitly require passing the owning class when creating it.
* extract self pointer class when adding a variant.
* put the flags on the single variants, we can not fully rule out that they will be 100% identical, if variants ever get allowed.
* Allow PFunction to work without a VMFunction being attached.
* The Variant for a function must store the prototype itself instead of relying on the VMFunction it points to. Otherwise it would not be possible to reference a prototype during compilation of the function because it does not exist yet.
* Give the variant a list of the function's argument's names, because these are also needed to compile the function.
* create an anonymous function symbol when the function gets registered to the builder. At this point we have all the needed information to set it up correctly, but later this is no longer the case. This is the most convenient info to have here because it contains everything that's needed to compile the function in the proper context, so it has to be present when starting compilation.
* added some preparations to implement special handling for weapons and custom inventory items, which can run action functions in another actor's context. This part is not active yet but the basics are present in SetImplicitArgs.
- fixed uninitialized counter variable in DECORATE parser.
- allow dottable_id of xxx.color so that the property parser can parse 'powerup.color'.
- fixed crash with actor replacement in script compiler.
- add the lump number to tree nodes because parts of the property parser need that to make decisions.
- removed test stuff.
- converted inventory.txt, player.txt and specialspot.txt to ZSCRIPT. These were the minimal files required to allow actor.txt to parse successfully.
- removed the converted files from the DECORATE include list so that these are entirely handled by ZSCRIPT now.
* everything related to scripting is now placed in a subdirectory 'scripting', which itself is separated into DECORATE, ZSCRIPT, the VM and code generation.
* a few items have been moved to different headers so that the DECORATE parser definitions can mostly be kept local. The only exception at the moment is the flags interface on which 3 source files depend.
