Going forwards, keep win32 build in svn once a tree is stable. Visual Studio 2010 users cannot convert our .dsp files, and ddk toolchain users couldn't either.
Applies the same logic as r1100294 on the 2.2.x branch.
Until the cmake build schema is entirely mature, these files are needed for command-line builds of the 2.4 tree, and are expected to change very little until the EOL of 2.4 branch.
The .dsp source files are not directly usable for any shipping version of MSVC/Visual Studio (post-Visual Studio 97 release), while the .mak exports of these projects are usable on any flavor of the MS nmake build environment. The .dsp source files are retained for those users wishing to import these projects into the modern vcproj/sln file format.