The test methods that take printf style input now have the printf
attribute. This enables format checks making oversights less likely.
Also fixed any existing errors in the code. Only the one in
test_binlog_fnc.cpp would've had an actual effect.
The binlogrouter tests can safely use the sync_slaves functionality of the
test framework as long as a sensible timeout is used.
Cleaned up the tests by removing redundant code and allocating classes
from the stack thus removing the need to handle memory allocation.
