mysql_client: Bump to 5.1.47 and fix build

MySQL build has been broken for quite some time due to the ./configure
inability to find out how to use 'ps' to find the PID of a running
program. This commit bumps MySQL to the latest version and adds a few
patches to fix various build issues, including the 'ps' issue.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>