Utilize LSB information before falling back to distro-specific sources of information

[andrewpollock]

I see

sysinfo/os.go

Line 32 in 85a453a

func (si *SysInfo) getOSInfo() {

uses the Linux distro-specific interfaces.

If the LSB is utilized, this would bring a degree of automatic extensibility to any Linux distro that implements this interface. I'm unsure about existing Go bindings for the LSB, though.