it can use it to switch to only quoting apostrophes by doubling
them when it is in effect. (Bug #10214)


include/my_sys.h:
  Add new escape_quotes_for_mysql() function
include/mysql_com.h:
  Add SERVER_STATUS_NO_BACKSLASH_ESCAPES
libmysql/libmysql.c:
  Use SERVER_STATUS_NO_BACKSLASH_ESCAPES in server_status to determine
  how mysql_real_escape_string() should do quoting.
mysys/charset.c:
  Add new escape_quotes_for_mysql() function that only quotes
  apostrophes by doubling them up.
sql/set_var.cc:
  Set SERVER_STATUS_NO_BACKSLASH_ESCAPES when MODE_NO_BACKSLASH_ESCAPES
  changes.
sql/sql_class.cc:
  Set SERVER_STATUS_NO_BACKSLASH_ESCAPES when necessary on thread creation.
tests/mysql_client_test.c:
  Add new test for sending NO_BACKSLASH_ESCAPES as part of server_status.