Merge branch 'vs12-generator' into release

Modules/CMakeVS12FindMake.cmake

Modules/FindBoost.cmake

Modules/InstallRequiredSystemLibraries.cmake

Modules/Platform/Windows-MSVC.cmake

Source/CMakeLists.txt

Source/cmDocumentVariables.cxx

Source/cmGlobalVisualStudio12Generator.cxx

Source/cmGlobalVisualStudio12Generator.h

Source/cmLocalVisualStudioGenerator.h

Source/cmVS12CLFlagTable.h

Source/cmVS12LibFlagTable.h

Source/cmVS12LinkFlagTable.h

Source/cmVisualStudio10TargetGenerator.cxx

Source/cmVisualStudioGeneratorOptions.cxx

Source/cmake.cxx

Source/cmparseMSBuildXML.py

Tests/CheckCompilerRelatedVariables/CMakeLists.txt

Tests/Preprocess/CMakeLists.txt

Tests/RunCMake/GeneratorToolset/RunCMakeTest.cmake

Tests/VSExternalInclude/CMakeLists.txt