Copied relevant test cases and code from the MySQL 5.6 tree
Testing of my_use_symdir moved to engines.


mysql-test/r/partition_windows.result:
  Updated result file
mysql-test/suite/archive/archive_no_symlink-master.opt:
  Testing of symlinks with archive
mysql-test/suite/archive/archive_no_symlink.result:
  Testing of symlinks with archive
mysql-test/suite/archive/archive_no_symlink.test:
  Testing of symlinks with archive
mysql-test/suite/archive/archive_symlink.result:
  Testing of symlinks with archive
mysql-test/suite/archive/archive_symlink.test:
  Testing of symlinks with archive
sql/log_event.cc:
  Updated comment
sql/partition_info.cc:
  Don't test my_use_symdir here
sql/sql_parse.cc:
  Updated comment
sql/sql_table.cc:
  Don't test my_use_symdir here
sql/table.cc:
  Added more DBUG_PRINT
storage/archive/ha_archive.cc:
  Give warnings for index_file_name and if we can't use data directory
storage/myisam/ha_myisam.cc:
  Give warnings if we can't use data directory or index directory