This patch is made as a part of MDEV-8334 to fix failing test in unit and
main test suite so that utf8mb3 characterset is recognized. Failing tests:
main.mysql_client_test
main.mysql_client_test_comp
unit.conc_basic-t
unit.conc_charset
unit.conc_connection
Instead of cheking GetConsoleWindow() function, we need to check
if GetConsoleCP() returns a positive number, otherwise we will use
the ANSI Code page Identifier for the system (GetACP()).
Default is OFF, which means MariaDB Connector/C
will be built without iconv support.
If set to OFF The API function mariadb_convert_string will always
return -1 and errorcode ENOTSUP.
According to https://msdn.microsoft.com/en-us/library/windows/desktop/dd317756(v=vs.85).aspx code page for latin1 is 1252, and not 850. The same for some other collations.
Changed "auto" charset detection to use only GetACP() on windows.
Since I guess C/ODBC is the only user of that feature, and because GetConsoleCP() returns OEM codepage, and not the default system codepage, which is used by DM as source codepage for recoding to unicode.
Added the character sets and collations described in CONC-299.
No additional test added, since charset/test_conc33 checks if all character sets and collations from server are supported.
