Move the VFS stuff into its own library.

lib/vfs/build.py

@@ -0,0 +1,31 @@
+from build.c import cxxlibrary
+
+cxxlibrary(
+    name="vfs",
+    srcs=[
+        "./acorndfs.cc",
+        "./amigaffs.cc",
+        "./appledos.cc",
+        "./applesingle.cc",
+        "./brother120fs.cc",
+        "./cbmfs.cc",
+        "./cpmfs.cc",
+        "./fatfs.cc",
+        "./fluxsectorinterface.cc",
+        "./imagesectorinterface.cc",
+        "./lif.cc",
+        "./machfs.cc",
+        "./microdos.cc",
+        "./philefs.cc",
+        "./prodos.cc",
+        "./roland.cc",
+        "./smaky6fs.cc",
+        "./vfs.cc",
+        "./zdos.cc",
+    ],
+    hdrs={
+        "lib/vfs/applesingle.h": "./applesingle.h",
+        "lib/vfs/sectorinterface.h": "./sectorinterface.h",
+        "lib/vfs/vfs.h": "./vfs.h",
+    },
+    deps=["+lib"])