PDB-549 Release notes for 1.6.3

Signed-off-by: Ken Barber <ken@bob.sh>
PDB-549 Some release note cleanups for 1.6.3

Signed-off-by: Ken Barber <ken@bob.sh>
Merge pull request #902 from kbarber/ticket/1.6.x/pdb-549-release-notes-163

PDB-549 Release notes for 1.6.3