Made change to mysqlimport to set character_set_database to binary to 
make importing various charsets/columns work correctly.


client/mysqlimport.c:
  BUG# 12123
  
  Added 'set @@character_set_database=binary' to make loading of tables with
  mixed charset types and non-latin characters load.
mysql-test/mysql-test-run.pl:
  BUG #12123
  
  Added $MYSQL_IMPORT in order to test mysqlimport bug.
mysql-test/mysql-test-run.sh:
  BUG #12123
  
  Added $MYSQL_IMPORT in order to test mysqlimport bug.
mysql-test/r/mysqldump.result:
  BUG #12123
  
  Added dumping and reloading (using mysql, mysqldump, and mysqlimport) to
  show that this fix handles dumping and reloading of non-latin1 charsets
  in table with different charset columns (mixing of charsets, also can be a
  UTF table with latin1 tables). Note the select before and after dump and 
  restore - should be exact.
mysql-test/t/mysqldump.test:
  BUG #12123
  
  Added dumping and reloading (using mysql, mysqldump, and mysqlimport) to
  show that this fix handles dumping and reloading of non-latin1 charsets
  in table with different charset columns (mixing of charsets, also can be a
  UTF table with latin1 tables). Note the select before and after dump and 
  restore - should be exact. (results of this)