If CMAKE_MAKE_PROGRAM is set to devenv, then GenerateBuildCommand
uses it just like we used to do for VS8 and VS9. Otherwise, it
still uses MSBuild.
This will let us run the CMake test suite through devenv and make
sure all the solution and project files we generate are load-able
and build-able by the VS 2010 IDE, not just MSBuild.
Inspired-By: Robert Lenhardt
The Express Edition does not come with 64-bit tools, but one can install
the "Microsoft Windows SDK v7.1" to get them. Detect this case and
check for the SDK. If found, set PlatformToolset to use the SDK tools.
Otherwise, fail with a concise and informative error.
This converts the CMake license to a pure 3-clause OSI-approved BSD
License. We drop the previous license clause requiring modified
versions to be plainly marked. We also update the CMake copyright to
cover the full development time range.