SysInfo: add "GetBuildTargetCpuFamily" function
SysInfo: add "GetXbmcBitness" function
SysInfo: refactoring IsOS64bit->GetKernelBitness, extend support for all platforms
Startup log: write information about target CPU; XBMC and OS bitness
Startup log: report number of CPU cores
Merge pull request #3232 from Karlson2k/Startup_log_03

Put even more information in startup log