kodi_arch.m4: refactoring for clarify and simplify configurations
[posix] Add "xbmc/posix" to include path, move platform specific include paths to kodi_arch.m4
Move all HAS_* and HAVE_* defines to platform specific PlatformConfig.h
Explicitly include "PlatformConfig.h" in every file that require any HAS_* or HAVE_* define, replace inclusion of "config.h"