* iuup: Check for IuUP Initialization retrans
* Fix attribute parsing on gcc 11.1.0
* mgcp_ratectr: refactor rate counter and set group name
* overview: add graph to show E1 integration * overview: fix graph "OsmoMGW used with OsmoMSC" * overview: fix graph "OsmoMGW used with OsmoBSC" * overview: update section limitations.