Progress (or lack of it) report:
First I found that I hadn't actually go libmysqlclient.10 installed, the locate database was out of date. So downloaded the package in 4.0 downloads in mysql that has the library, so now I could compile the php-mysql package.
BUT the api client for mysql in phpinfo now show mysql 3.23 so that was no good. I don't understand what the php-mysql package does. Do you need a new one each time you update php and it works with any version of mysql, or visa versa? Or is there a separate version for each combination of PHP/MySQL.
After trying to install a binary - no joy.
Trying to install from source using these instructions http://fedoranews.org/contributors/tony_smith/mysql/
and getting an error error: line 356: Package does not exist: %post Max
I have given up and am trying to reinstall 3.23.....
By the way - to tell builds where to look for libraries, you can add paths to this file: ld.so.conf which is in /etc on my system.
I will have to give this another go sometime and will post any progress.