API updates Q1 2016

Today I have pushed another incremental update to the API, and to our API documentation.

The major changes are a method to find the latest data for a single item or a single host, as well as a method to find data fresher than a certain timepoint.

Also included is a conveinence function to prepare history requests. It will pre-calculate the necessary requests to fullfil an arbitary range of data.

This is to help cache effectivity of history data requests.