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.
Split cmVisualStudioGeneratorOptions core functionality out into a base class cmIDEOptions. It will be useful for other generators.
Move the cmVS7FlagTable type out of the VS generators and rename it to cmIDEFlagTable. It will be useful for other generators.