In BUG#30244 added FOUND_ROWS() as an unsafe function, but that
works only in mixed mode under 5.1. There is a workaround that
can be used in statement-based mode either under 5.0 or 5.1
where the result of FOUND_ROWS() is stored into a user vari-
able and used that way instead. This will replicate correctly
even under statement-based replication, since it will write
a User_var entry to the binary log. For some other cases, the
value has to be passed explicitly.

This patch adds tests to demonstrate that the workarounds docu-
mented for statement-based replication works as advertised, and
does more extensive tests for cases that does not work under sta-
tement-based replication actually work under mixed mode by switch-
ing to row-based replication.