Bug-fixes and improvements in init scripts

This MR makes the following changes to the init scripts:

• Implements the missing functions aa_log_action_start, aa_log_action_end, aa_log_daemon_msg and aa_log_end_msg in parser/rc.apparmor.redhat and parser/rc.apparmor.slackware, all of which are required by rc.apparmor.functions. aa_log_daemon_msg and aa_log_end_msg are simply aliases for aa_log_action_start and aa_log_action_end respectively, since they seem to be used in the same way. I also reordered the aa_log_* functions in the init scripts to the order they're listed in the header of rc.apparmor.functions, hopefully to make it clear which ones are missing if this happens again in future.
• Removes an unnecessary call to aa_log_action_end in parser/rc.apparmor.functions: the call to aa_log_failure_msg on the previous line already does the job, and the further call to aa_log_action_end outputs another unnecessary "failure" message. Also a minor improvement to the way in which the output of apparmor_stop is displayed in Slackware.
• Removes parser/rc.apparmor.debian, because it isn't used downstream, and hasn't been for quite some time: Debian ships its own init script that calls functions in (a heavily-patched version of) rc.apparmor.functions directly. The SuSE init script was dropped last year (c9bf36dd) for the same reason.