Add FLAGDIR utility and clean DOS utility build files

Add a NetWare-style FLAGDIR implementation for directory attributes and
register it in the multi-call DOS utility dispatcher.  The new command
supports the 386-style directory flags Normal, System, Hidden,
DeleteInhibit, Purge and RenameInhibit, and formats output close to the
Novell FLAGDIR tool for simple mapped paths.

Update the DOS utilities install/build metadata so flagdir.exe is emitted
alongside the other public tools.  Adjust the Open Watcom CMake build to
compile C sources into the build directory instead of leaving object files
in the source tree.

Move the historical Borland/TASM build files into doc/ to keep the active
source directory focused on the modern Watcom/CMake build.

CMakeLists.txt

@@ -62,10 +62,39 @@ if(MARS_NWE_BUILD_DOSUTILS)
                 -fo="${CMAKE_CURRENT_BINARY_DIR}/kern.obj"
                 "${CMAKE_CURRENT_SOURCE_DIR}/kern_wasm.asm"
         DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/kern_wasm.asm"
-        WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}"
+        WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}"
         VERBATIM
     )
 
+    set(DOSUTILS_OBJECTS)
+    foreach(src IN LISTS DOSUTILS_C_SOURCES)
+        get_filename_component(obj_name "${src}" NAME_WE)
+        set(obj "${CMAKE_CURRENT_BINARY_DIR}/${obj_name}.obj")
+        list(APPEND DOSUTILS_OBJECTS "${obj}")
+
+        add_custom_command(
+            OUTPUT "${obj}"
+            COMMAND "${CMAKE_COMMAND}" -E env ${OPENWATCOM_ENV}
+                    "${OPENWATCOM_WCL}"
+                    -q
+                    -zq
+                    -bt=dos
+                    -ml
+                    -0
+                    -c
+                    -fo="${obj}"
+                    "${CMAKE_CURRENT_SOURCE_DIR}/${src}"
+            DEPENDS
+                    "${CMAKE_CURRENT_SOURCE_DIR}/${src}"
+                    "${CMAKE_CURRENT_SOURCE_DIR}/net.h"
+                    "${CMAKE_CURRENT_SOURCE_DIR}/kern.h"
+                    "${CMAKE_CURRENT_SOURCE_DIR}/c32ncp.h"
+                    "${CMAKE_CURRENT_SOURCE_DIR}/nwcrypt.h"
+            WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}"
+            VERBATIM
+        )
+    endforeach()
+
     add_custom_command(
         OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/net.exe"
         COMMAND "${CMAKE_COMMAND}" -E env ${OPENWATCOM_ENV}
@@ -77,15 +106,12 @@ if(MARS_NWE_BUILD_DOSUTILS)
                 -0
                 -k32768
                 -fe="${CMAKE_CURRENT_BINARY_DIR}/net.exe"
-                ${DOSUTILS_C_SOURCES}
+                ${DOSUTILS_OBJECTS}
                 "${CMAKE_CURRENT_BINARY_DIR}/kern.obj"
         DEPENDS
-                ${DOSUTILS_C_SOURCES}
+                ${DOSUTILS_OBJECTS}
                 "${CMAKE_CURRENT_BINARY_DIR}/kern.obj"
-                net.h
-                kern.h
-                nwcrypt.h
-        WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}"
+        WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}"
         VERBATIM
     )