RELEASE-NOTES: sketch out 5.3 RC1 notes from bk changes -fmrbk-5.2.1..+
RELEASE-NOTES: sketch out 5.3 RC1 notes from
bk changes -fmrbk-5.2.1..+

bk: 4e17719dr7x3eoY_POEuaW-b3ct91A
bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper