Clearscope is a dangerous context and should be limited to the minimum extent possible and preferably be blocked in user code.
This may still need some work on const functions but better have it in now.
- handle these powerups by actual item checks instead of cheat flags. (The same should also be done for the Frightener and Buddha but those are a bit more complex because they are also real cheats.)
- ensure that actor defaults contain a valid virtual table and class pointer so that they can actually use virtual and class-dependent method functions. This is needed for retrieving script variables from them.
- added some helpers to set scripted member variables through the native property parser.
Unfortunately some classes, e.g. PowerMorph, MorphProjectile and the powerup contain some that cannot be handled through the 'property' definition on the script side so they need to be done from the native side.
This revealed an interesting bug: When the berserk fadout formula was changed in 2005 the result was essentially broken, resulting in values around 7000 - it only worked by happenstance because the lower 8 bits of the resulting values just happened to work to some degree and never overflowed. But the resulting fade was far too weak and a slightly different handling of the color composition code for the VM made it break down entirely.
This restores the pre-2005 formula but weakened intensity which now comes a lot closer to how it is supposed to look.
