IETF 98 Hackathon - implement YANG 1.1, ietf-yang-library.yang, ietf-netconf-notifications.yang, stability and interoperability, release 2.10

A good amount of work was done. A new tool for scripting test case sessions called litenc https://github.com/vlvassilev/litenc was created for testing netconfd: https://sourceforge.net/p/yuma123/git/ci/master/tree/netconf/test/netconfd/edit-config/session.duplicated-list-entry.litenc.py Important work involving interoperability tests and resolution of the detected issues. Some YANG 1.1. features were implemented, ietf-yang-library was not implemented. The 2.10 release was postponed.