Initial commit: Complete open-source Decal rebuild

All 5 phases of the open-source Decal rebuild:

Phase 1: 14 decompiled .NET projects (Interop.*, Adapter, FileService, DecalUtil)
Phase 2: 10 native DLLs rewritten as C# COM servers with matching GUIDs
  - DecalDat, DHS, SpellFilter, DecalInput, DecalNet, DecalFilters
  - Decal.Core, DecalControls, DecalRender, D3DService
Phase 3: C++ shims for Inject.DLL (D3D9 hooking) and LauncherHook.DLL
Phase 4: DenAgent WinForms tray application
Phase 5: WiX installer and build script

25 C# projects building with 0 errors.
Native C++ projects require VS 2022 + Windows SDK (x86).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Installer/Res/howto.txt

@@ -0,0 +1,78 @@
+How to make a new Decal installer:
+
+Update from CVS (or make sure you have the version of the code you want to release)
+
+Update readme.rtf to reflect the current state of Decal
+
+Open the provided VSI project files (DecalInstaller.sln and DecalInstaller.wip)
+
+Change the Product Name, Product Code, Version, Version string in the registry, and whatever else needs to be changed in the installer (but NOT the filename)
+
+Build a new installer
+
+Open Install.vbs 
+
+Add a new uninstall entry for the current Product code using the others as an example (AllProducts.Add "<version>", "<GUID>")
+
+Change the ThisVersion constant to reflect the new version number
+
+Save and Close Install.vbs and VSI
+
+Open EnZip 3.00 ( freeware: http://www.cpam.freeserve.co.uk/ )
+
+Choose File, New Archive... (or hit Ctrl-N)
+
+Give a filename such as "Decal_2000.zip" for Decal 2.0.0.0
+
+Add Decal.msi and Install.vbs to the files, using maximum compression (available on the Options tab)
+
+Choose Tools, Create Self-Extractor... (or hit Shift-X)
+
+Click Next to customize the extractor
+
+Click Next to NOT have a message box
+
+Click Next to have it extract to the TEMP folder
+
+Change the Tile Caption to "Decal Installer" and Click Next
+
+Type "Install.vbs" in the Command box, leave the Parameters box empty, then hit Next
+
+Click the Change Icon... button and select the Decal.ico from the source/Installer/Res folder
+
+Select the first icon and Click Ok, then Click Next
+
+Uncheck Display Run Command Checkbox
+
+Check Unzip Automaticly
+
+Make sure Default to overwrite files without prompting is selected
+
+Click Next, then Click Yes to bypass the warning
+
+Verify your options in the displayed listbox and then hit Create (this may look like it's not doing anything, but it is)
+
+When it completes, hit Test Self-Extracting ZIP file now 
+
+If everything went ok, it should display a command prompt window while previous Decal versions are uninstalled, then close and start the Decal installer MSI
+
+Click Close, then close EnZip
+
+
+VERIFY!!!!!!!!
+Make sure there is only ONE add/remove entry for Decal
+Make sure there is only ONE Decal group in the Start Menu
+Make sure there is only ONE Decal icon on the Desktop
+Make sure ALL the file versions are correct
+Load up Decal and make sure it runs properly (to verify things such as registry values)
+Attempt to delete all of the shortcuts, then open IE. If the installer starts and repairs the shortcuts something is wrong.
+Test the FavIcon creation
+Generally kick it around and attempt to break it
+
+COMMIT!!!!
+Commit your new changes with a tag (so that the installer can be rebuilt in it's current state at any time)
+If this is a release version (not BETA), create a branch for bugfixes
+Upload the binary to SourceForge (see sf.net instructions)
+Test the download and verify you get the same file you uploaded
+Change the homepage of decaldev.sf.net to point to the new download
+