binlog, replication aborts

In SBR or MBR, the schema name is not being written to the binlog
when executing a LOAD DATA statement. This becomes a problem when
the current database (lets call it db1) is different from the
table's schema (lets call it db2). For instance, take the
following statements:
  
  use db1;
  load data local infile 'infile.txt' into table db2.t

Should this statement be logged without t's schema (db2), when
replaying it, one can get db1.t populated instead of db2.t (if
db1.t exists). On the other hand, if there is no db1.t at all,
replication will stop.

We fix this by always logging the table (in load file) with fully
qualified name when its schema is different from the current
database or when no default database was selected.