Decode Trendlog entries

[stevedh]

I'm pretty sure that printing readrange data wasn't implemented; this adds it by adding a new structure to hold ReadRange data and then mapping it to BACNET_APPLICATION_DATA_VALUE. It seems like the Log_Entry encoding isn't quite 1:1 with BACNET_APPLICATION_DATA_VALUE but I feel like this is what most people will want.

Let me know if the organization + decoding logic looks OK.

[stargieg]

I am also interested in this function. In this branch https://github.com/bacnet-stack/bacnet-stack/compare/master...stargieg:bacnet-stack-upstream:stevedh-feature/readrange-decode I have updated and hopefully improved the function. I don't understand what you mean by "bacnet_date_context_decode". "Date and Time" is a "BACNET_APPLICATION_TAG_DATE" and not a "context_tag". I tried to change it but without success.

[MightyPork]

I have some packet dumps with trendlogs if it could help move this forward (but they use segmentation because of the large packet size)