SHP support in GDAL vs. GDAL-OGR

[Ben Discoe]

I notice that there is SHP file support in two place in GDAL:

gdal/fmts/shapelib
gdal/ogr/ogrsf_frmts/shape

As far as i can tell, there are some differences, but there is substantial
overlap as well, e.g. there are identical copies of 'shpopen.cpp', etc.

Some questions:

1. Why aren't the duplucate modules conflicting? I've studied the VC
makefiles, but it's not very clear... perhaps the first (fmts/shapelib)
isn't getting built?

2. I used to be able to call shapelib directly (function SHPOpen() etc.) and
link with GDAL to get the functions. Now with 1.1.6, the linker says the
symbols (like SHPOpen) are undefined. As far as i can tell, SHPAPI_CALL was
"" in both 1.1.5 and 1.1.6, so i don't know why this would have changed.
Why did it stop working, what do i need to do to call the shapelib inside
GDAL? Do i need to set SHPAPI_CALL=CPL_DLL?

Thanks,
Ben