Add 3GPP TS 29.337 V15.0.0 (2018-06) Add AVPs: - SM-Delivery-Outcome-T4, Enumerated, code 3200, section 6.3.1 - Absent-Subscriber-Diagnostic-T4, Enumerated, code 3201, section 6.3.2 - Trigger-Action, Unsigned32, code 3202, section 6.3.6 - MTC-Error-Diagnostic, Unsigned32, code 3203, section 6.3.7

The digested changelog can be found under:
 contrib/debian/changelog
 
You can also find the exhaustive list of change using mercurial history, 
or at the following URL: http://www.freediameter.net/hg/freeDiameter/shortlog