dyn_array_open(): mention the size limit
mtr0log.ic, mtr0log.h:
  mlog_open(): mention the size limit


innobase/include/mtr0log.h:
  mlog_open(): mention the size limit
innobase/include/mtr0log.ic:
  mlog_open(): mention the size limit
innobase/include/dyn0dyn.h:
  dyn_array_open(): mention the size limit