We add new algorithm and tools to implement a much simplified jet reconstruction chain. The new tools and algs live together with the RunII ones so we can transition smoothly to the new ones when everything is implemented. This MR concerns the first tools/alg re-written in sept 2019 by the JetEtmiss group. The WIP label is here just to give time to all JetEtmiss developers to give feed back. This is followed-up in ATLJETMET-1170