ChangeLog: Update with fuller description for 2.0.0 from ChangeLog_highlights.rst
ChangeLog: Update with fuller description for 2.0.0 from
ChangeLog_highlights.rst

bladams/pymssql,pymssql/pymssql,JimDennis/pymssql,JimDennis/pymssql,JimDennis/pymssql,ramiro/pymssql,ramiro/pymssql,Aloomaio/pymssql,bladams/pymssql,klothe/pymssql,pymssql/pymssql,bladams/pymssql,ramiro/pymssql,zerolugithub/pymssql,klothe/pymssql,klothe/pymssql,Aloomaio/pymssql,zerolugithub/pymssql,Aloomaio/pymssql,zerolugithub/pymssql