Taking code from before BUG#22583 and incorporating as events to be able
to read old events. Also incorporating old pack and unpack functions
into patch.


client/Makefile.am:
  Adding files log_event_old.{h,cc} and rpl_record_old.{h,cc}
client/mysqlbinlog.cc:
  Adding log_event_old.cc.
libmysqld/Makefile.am:
  Adding files log_event_old.{h,cc} and rpl_record_old.{h,cc}
sql/CMakeLists.txt:
  Adding files log_event_old.{h,cc} and rpl_record_old.{h,cc}
sql/Makefile.am:
  Adding files log_event_old.{h,cc} and rpl_record_old.{h,cc}
sql/log_event.cc:
  Adding code to read pre-GA rows events.
sql/log_event.h:
  Refactoring to support inheritance and including "old" events definitions.
sql/log_event_old.cc:
  New BitKeeper file ``sql/log_event_old.cc''
sql/log_event_old.h:
  New BitKeeper file ``sql/log_event_old.h''
sql/rpl_record_old.cc:
  New BitKeeper file ``sql/rpl_record_old.cc''
sql/rpl_record_old.h:
  New BitKeeper file ``sql/rpl_record_old.h''