VS6: Hardcode id_machine_6 for compiler detection

id_machine6 is never set to an other value than x86. So it is
safe to remove the replacements with "x86" directly.
VS10: Do not set the TargetMachine when detecting the compiler

The Microsoft linker is intelligent enough to detect the target
machine type depending on the input files. This allows us to
get the target architecture from the compiler instead of
maintaining the mapping to the platform name.
VS: Set CMAKE_VS_PLATFORM_NAME for VS7 and VS71 too

Move the code which sets CMAKE_VS_PLATFORM_NAME from
cmGlobalVisualStudio8Generator to cmGlobalVisualStudio7Generator.
VS: Replace ArchitectureId with PlatformName

Since we do not need the information about the target architecture
we can use the PlatformName only to specify the this information.
This also removes setting of the MSVC_*_ARCHITECTURE_ID variable
which is not required, because this variable gets set by the
compiler detection code in CMAKE_DETERMINE_COMPILER_ID_CHECK().
VS12: Remove duplicated overload of UseFolderProperty()

cmGlobalVisualStudio11Generator generator already defines the same
function body, which makes the additional overload useless.
Fix detection of WinCE SDKs with 64bit verion of CMake

Use cmSystemTools::KeyWOW64_32 instead of KeyWOW64_Default to
make sure that the correct part of the registry is read.
VS: Unify how the name of the generator is specified

Use the value of the provided argument instead of using a fixed
character buffer. This aligns VS10+VS11+VS12 with VS8+VS9.
Merge topic 'vs-cleanup'

c90151b VS: Unify how the name of the generator is specified
3873d29 Fix detection of WinCE SDKs with 64bit verion of CMake
40a4302 VS12: Remove duplicated overload of UseFolderProperty()
b02f09d VS: Replace ArchitectureId with PlatformName
4b15dc8 VS: Set CMAKE_VS_PLATFORM_NAME for VS7 and VS71 too
60e568c VS10: Do not set the TargetMachine when detecting the compiler
dfbfe6f VS6: Hardcode id_machine_6 for compiler detection