Add LTEMM and SDPP drivers for XTMax (#27)

* Add gitattributes to handle line endings.

* Import the unmodified LTEMM source.

From https://www.lo-tech.co.uk/wiki/LTEMM.EXE.

* Add DOSBox and TASM for build.

* Add build script for LTEMM.

* Modity LTEMM driver for XTMax.

* Import the unmodified SDPP source.

From https://forum.vcfed.org/index.php?threads/sd-card-to-parallel-port-driver-for-msdos-ver-1-1.42008/.

* Add Borland C++ 3.1 (Minimal) for build.

* Add build script for SDPP.

* Modify SDPP driver for XTMax.

* Commit pre-built binaries for LTEMM and SDPP.

* Reorganize the drivers into a new folder.

XTMax/Drivers/LTEMM/.vscode/tasks.json

@@ -0,0 +1,20 @@
+{
+    // See https://go.microsoft.com/fwlink/?LinkId=733558
+    // for the documentation about the tasks.json format
+    "version": "2.0.0",
+    "tasks": [
+        {
+            "label": "Build in DOSBox",
+            "type": "shell",
+            "command": "..\\Driver_Build_Tools\\DOSBox\\DOSBox.exe -conf Build.conf",
+            "options": {
+                "cwd": "${workspaceFolder}"
+            },
+            "problemMatcher": [],
+            "group": {
+                "kind": "build",
+                "isDefault": true
+            }
+        }
+    ]
+}