mysql_real_escape_string() function was found insecure when sql_mode was set to
NO_BACKSLASH_ESCAPES. mysql_real_escape_string() function reports error when sql_mode
is set to NO_BACKSLASH_ESCAPES.

Newly introduced API function mysql_real_escape_string_quote() should be used instead.
Additional char type parameter allows to specify, which character should be doubled.
Doubled character is a quote character of the identifier or a string within a SQL query.

client/mysql_secure_installation.cc
client/mysqldump.c
client/mysqlimport.c
client/mysqlshow.c
  Every occurrence of mysql_real_escape_string() replaced with
  mysql_real_escape_string_quote().

include/errmsg.h
  Insecure API error message code added (CR_INSECURE_API_ERR / 2062).

libmysql/errmsg.cc
  Insecure API error message text added.

include/my_sys.h
mysys/charset.c
  escape_quotes_for_mysql() extended to support additional parameter (char quote).

include/mysql.h
include/mysql.h.pp
  mysql_real_escape_string_quote() function declaration added.

libmysql/CMakeLists.txt
  mysql_real_escape_string_quote() function added to the client API set.

libmysql/libmysql.cc
  mysql_real_escape_string_quote() function definition added.

libmysql/libmysql.def
libmysqld/libmysqld.def
  mysql_real_escape_string_quote() function added to the lib exports.

mysql-test/r/mysqlshow.result
mysql-test/t/mysqlshow.test
  MTR test extended to support grave accent (`) table name tests.

sql/sql_initialize.cc
  escape_quotes_for_mysql() call replaced with escape_string_for_mysql().

tests/mysql_client_test.c
  Tests of the mysql_real_escape_string_quote() function added.