Add OS information into logs/debug output for ld-decode-tools and ld-decode

[simoninns]

Since there are many users running in unsupported environments it is getting really hard to tell if issue reports are really issues at all. The ld-decode tools (and probably ld-decode) should report the underlying OS and version in all debug so if bugs are reported on unsupported systems they can be pushed to the port maintainer for first-pass analysis.

[happycube]

This turns out to be a pretty easy change using the platform library. The output for Linux isn't as good as using /etc/lsb-release, but it should always work.

[happycube]

Done, at least for the json file. missed the debug logs.

[simoninns]

I need to modify the tools output too... So note when ld-decode is done and I'll update when ld-decode-tool match... then we can close.

[harrypm]

It would be good if this also stores inital command used for decoding aswell so user error can be easily catched/pointed out.