New MSVC property sheet for Multi-threaded XPDEV builds and usage:

defines XPDEV_THREAD_SAFE (not currently used in Windows builds) and
LINK_LIST_THREADSAFE (notice the inconsistent use of underscore :-)

src/sbbs3/ntsvcs.vcxproj

@@ -36,6 +36,7 @@
     <Import Project="..\smblib\smblib.props" />
     <Import Project="..\build\undeprecate.props" />
     <Import Project="..\build\target_ia32.props" />
+    <Import Project="..\xpdev\xpdev_mt.props" />
   </ImportGroup>
   <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="PropertySheets">
     <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
@@ -44,6 +45,7 @@
     <Import Project="..\smblib\smblib.props" />
     <Import Project="..\build\undeprecate.props" />
     <Import Project="..\build\target_ia32.props" />
+    <Import Project="..\xpdev\xpdev_mt.props" />
   </ImportGroup>
   <PropertyGroup Label="UserMacros" />
   <PropertyGroup>

src/sbbs3/sbbscon.vcxproj

@@ -36,6 +36,7 @@
     <Import Project="..\smblib\smblib.props" />
     <Import Project="..\build\undeprecate.props" />
     <Import Project="..\build\target_ia32.props" />
+    <Import Project="..\xpdev\xpdev_mt.props" />
   </ImportGroup>
   <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="PropertySheets">
     <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
@@ -44,6 +45,7 @@
     <Import Project="..\smblib\smblib.props" />
     <Import Project="..\build\undeprecate.props" />
     <Import Project="..\build\target_ia32.props" />
+    <Import Project="..\xpdev\xpdev_mt.props" />
   </ImportGroup>
   <PropertyGroup Label="UserMacros" />
   <PropertyGroup>