Improve OS detection for Linux systems

Linux agents collect wrong os information (Distribution/Version) if lsb_release is present.

On OS_Version field (you can see it on Enterprise Manager, machine, advanced properties but you can retrieve it by reading MACHS_AUX or by using API) you get the LSB_VERSION instead of an user friendly name. So you know the machine architecture but you can't recognize the os/version where the agent is installed.

Please improve it.