TINSEL: Discworld 1 Script Patches

[sluicebox]

This PR contains four script patches for Discworld 1 bugs and some new debugger commands. Each bug is in the original game and has a ticket going back 8-14 years. I am new to Tinsel, so please check my work.

First to clarify a version issue: All DW1 .GRA versions have identical resource files, excluding demos. Only the .TXT and audio files are different. The oldest ticket was left open because it was misdiagnosed as only affecting the European .GRA version, but I reproduced it in the English-only .GRA, because they're identical, so I don't know what went wrong there. The important thing is that all the .GRA files are the same in all versions so the results are consistent and you only need to write one patch for them.

• Amazon Speech interrupted by Starfish coin flip: We fixed this in the DOS English-only .SCN version, but it also exists in .GRA versions and Mac English-only .SCN. I've adapted the fix for both. The bug was fixed in later versions by doing the same thing as our patch: removing the StopSample call. https://bugs.scummvm.org/ticket/6013

• Act 4 invisible city guard crash: In Act 4 the city guards are not at the city gate, but the polygon for one of them is still active. Clicking it crashes. This is a bug in .GRA versions. The problem is that the polygon has an incorrect ID, preventing its KillTag call from doing anything. In later versions the polygon was updated to match the expected ID in the script. I fixed this by adding a KillTag call with the real ID. https://bugs.scummvm.org/ticket/10659

• Act 3 floating calculate button: The "what are the odds?" calculation window doesn't remove the calculate button from the screen when clicking outside the window. This is another .GRA bug. The problem is in the films: the film for pressing the button removes it, but the film for clicking outside the window does not. The film was fixed in .SCN versions. Since there is no missing script code to add, I've worked around this by adding a Play call so that the button always animates and removes itself. This is appropriate because both actions trigger the same calculations and responses from the guard. https://bugs.scummvm.org/ticket/10658

• L-Space barman conversation window: The window doesn't respond to clicking on the stop-conversation icon. Another .GRA bug. The ScanIcon switch statement in the script is missing a case statement, so I added it. https://bugs.scummvm.org/ticket/10661

[bluegr]

Excellent work, thanks!