Add configuration option to the base/rom extension to make the toolchain (ARMCC/GCCE) known to the preprocessor stage of romb build.
<?xml version="1.0" encoding="Windows-1252"?>
<VisualStudioPropertySheet
ProjectType="Visual C++"
Version="8.00"
Name="debug"
>
<Tool
Name="VCCLCompilerTool"
PreprocessorDefinitions="_DEBUG"
/>
<UserMacro
Name="KillPythonExe"
Value="$(OutDir)\kill_python_d.exe"
/>
</VisualStudioPropertySheet>