There was hanging at binlog_commit by a thread executing autocommit query.

The hang appeared to be due to an overly condtion for early return 
from binlog_commit introduced by bug#20265 fix.

Fixed with reverting the logic back to 5.0 version.


mysql-test/extra/binlog_tests/binlog.test:
  added a regression test
mysql-test/r/binlog_row_binlog.result:
  results changed
mysql-test/r/binlog_stm_binlog.result:
  results changed
sql/log.cc:
  Removing `all' conjuction arg from early return condition.
  There is nothing to execute by transaction if trx_data is empty.
  
  The work for rotate_and_purge is delayed till TC_LOG::unlog 
  (same as in 5.0 code)
sql/log.h:
  singed because there are assert on positiveness