v2.1.0 improve reliability of GoFlow2 and library bugfixes: * decoder: missing time received ns in netflow v5 (#209) * decoder: fix netflow flowsets (#218) * decoder: improve BasicTemplateSystem (#233) * decoder: ipfix have max size (#237) * decoder: do not stop reading sets (#239) * decoder: check etype size (#252) * producer: fix fragments for IPFIX (#196) * producer: bugfix of sampling mapping for ipfix (#207) * producer: add missing renderer for bgp_next_hop (#210) * producer: fix fragment for NetFlow (#215) * producer: increase performance of sampling rate lookup (#264) * transport: fix kafka default partitioning (#246) features: * goflow2: allows using a single port for multiple protocols (sFlow, NetFlow, IPFIX) (#197) * goflow2: add additional parameters in listen URL (#208) * goflow2: handle panic (#254) * producer: add datetime render (#225)