core: add --check command to gather system information

Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
core: add platform information to --check

Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
socketstatistics: ss command only available under Linux - exit programm

Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>