A left over from the VC6 project files, so mainly cosmetic in Visual
Studio .NET as it can handle both comma and semi-colon characters for
separating multiple pre-processor definitions.
However, the IDE uses semi-colons if the value is edited, and as such,
this may cause problems in future for anyone updating the files or
merging patches.
Used the Visual Studio IDE to correct the separator character.
As with commit 11397eb6dd, use $(TargetDir) and $(TargetName) for the
Import Library output rather than $(OutDir)\$(ProjectName)d.lib and
$(OutDir)\$(ProjectName).lib.
Carrying on from commit 11025613b9 added VC7.1 project files which are
capable of supporting side-by-side compilation, as well as support for
some of the third-party libraries curl uses.
