SysInfo: add GetModelName() and GetManufacturerName() functions for all platforms (currently only Darwin, Win32 and Android return meaningful values)
Startup log: unify startup log strings for all platforms, log manufacturer and model name
SysInfo::GetUserAgent: included win32 refactored part, updated code to use new functions
Rename kernelVersion->osVersionInfo, SYSTEM_KERNEL_VERSION -> SYSTEM_OS_VERSION_INFO
Old name was incorrect as XBMC provide much more information than just kernel version
SystemInfo: cleanup: remove unused platform-specific, outdated functions and ancient declared-only functions
[win32] SysInfo::GetKernelBitness: update for Vista+ only code, refactoring
[win32] SysInfo::GetKernelCpuFamily: use GetNativeSystemInfo() instead of GetSystemInfo()
SysInfo::HasVideoToolBoxDecoder: small refactoring and unification
SysInfo::GetBuildTargetPlatformName: update platform names to match GetOsName() values
SysInfo: add GetBuildTargetPlatformVersionDecoded() and update GetBuildTargetPlatformVersion()
Startup log: use SysInfo::GetBuildTargetPlatformVersionDecoded() function
Startup log: fix log with empty CPU string
SysInfo: add GetUsedCompilerNameAndVer(), Startup log: use updated CSysInfo::GetUsedCompilerNameAndVer()