Implemented strtolW/strtoulW in libwine_unicode and used it to replace
wcstol and friends.

diff --git a/dlls/setupapi/install.c b/dlls/setupapi/install.c
index 9390d04..e3f8adf 100644
--- a/dlls/setupapi/install.c
+++ b/dlls/setupapi/install.c
@@ -315,7 +315,7 @@
 
         if (type == REG_DWORD)
         {
-            DWORD dw = str ? wcstol( str, NULL, 16 ) : 0;
+            DWORD dw = str ? strtolW( str, NULL, 16 ) : 0;
             TRACE( "setting dword %s to %lx\n", debugstr_w(value), dw );
             RegSetValueExW( hkey, value, 0, type, (BYTE *)&dw, sizeof(dw) );
         }