Both games use an additional parameter for show.mouse and hide.mouse.
Ignoring these confused the script parser, which started parsing junk.
Fixes bugs #3577754 and #3426946.
Was introduced during refactoring to SCI-like opcode handling.
Also restored original comments about opcode parameter differences
between AGI versions.
The experiment tries to implement the program control of the V1 interpreter.
Maybe it is better to add another method for doing that once the workings of
it are more clear.
* Instruction tables are now defined in opcodes.{cpp,h}.
* Move opcode handlers from Agi::AgiEngine to Agi
* Opcode handlers take as parameter a pointer to AGI state (AgiGame)