Update to 4.023

Changelog:
2013-04-12 Patrick Galbraith et open source community <patg at patg dot net> (4.023)
* Fix primary_key_info result ordering - https://github.com/CaptTofu/DBD-mysql/pull/39 - Dagfinn Ilmari Manns奪ker
* allow compilation with msvc - https://github.com/CaptTofu/DBD-mysql/pull/37 - Walde Christian
* just to set MYSQL_OPT_WRITE_TIMEOUT and MYSQL_OPT_READ_TIMEOUT by dsn - https://github.com/CaptTofu/DBD-mysql/pull/36 - Naosuke Yokoe
* just remove unnecessary "my" - https://github.com/CaptTofu/DBD-mysql/pull/34 - Shoichi Kaji
* eval $ExtUtils::MakeMaker::VERSION requires for old ExtUtils::MakeMaker - https://github.com/CaptTofu/DBD-mysql/pull/32 - Daisuke Murase
* Updated documentation to reflect that bugs will be reported at rt.cpan.org
* Updated version
* Chased tail finding issue with -1 being converted to max unsigned int in PS mode

(ryoon)