fix 1:#818 Master slave synchronization - There will be too many tuples problem

Cause:
Tianmu::dbhandler::TianmuHandler::current_position This variable is not initialized. In some cases,
a large value may cause too many tuples problem.
Solution: Initialize the variable

fix 2:#819 Master slave synchronization - Primary key conflict problem

Solution: Modify the modification logic of master slave synchronization, so that the delete and update operations do not follow the primary key logic

Supplement

sql/sql_insert.cc
Fix the problem that the insert statement will not generate binlog in the delayed insert mode
storage/tianmu/handler/tianmu_handler.cpp
Fix the binlog error of the line format generated by the tianmu engine