Fixed daemon rescue shell commands

'&&' is the logical AND operator and will simply run the "killer" subshell if
the init.d script returned success. What is needed is '&' to run the init script
in the background, otherwise $! is unset too. The sleep needs to be longer
because some daemons like mysql with lots of dirty buffers can take a while to
stop and we don't want to abort that attempt too early.