Added new test cases, fixed bugs in relation to those


mysql-test/r/partition_charset.result:
  New test case
mysql-test/r/partition_list.result:
  New test case
mysql-test/t/partition_list.test:
  New test case
sql/partition_info.cc:
  Missing initialisation
sql/sql_partition.cc:
  key_restore made use of field->ptr in VARCHAR fields and
  when used with REPLACE it caused the key_restore to
  become against table->record[0] when buf pointed to
  table->record[1]