The code that checks for stop events is not needed as it is only used for
log messages. These aren't really useful to the end user so they can be
removed.
Moved the modification of the event size in case binlog checksums are
enabled outside of the handle_one_event function. This will make it
possible to move most of the processing done inside it into a reusable
class of its own.
Also fixed the memory leak for the event data.