Cleanup in ac-tile MPM

Remove return from void functions.
Add some commments
Remove inline on functions where it doesn't make sense.
Rewrote if statement to be more clear.
When assigning Pattern IDs pids, check Case flags

This fixes bug 1110. When assigning PIDs, use the NO_CASE flag when comparing
for duplicates. The state of the flag must be the same, but also use the same
type of comparisons when checking for duplicates.

Previously, "foo":CS would match with "foo":CI when it should not.
and "foo":CI would not match "FoO":CI when it should. Both of those
cases are fixed with this change.

This then allows simplifying the use of pid in MPMs because now if they
pids match, then so do the flags, so checking the flags is not required.
Remove case_state usage

The case_state in MPMs was just to track when a pid could have no-case and
case-sensitive matches for the same PID. Now that can't happen after fixing
bug 1110, so remove the code and storage for case_state.
Store case-insensitive patterns as lowercase.

This is required because SCMemcmpLowercase() expects it first argument
to be already lowercase for the comparison. This is done by using
memcpy_tolower() for NO_CASE patterns.

This addresses code review comments from Victor.
Move memcpy_lower() into new util-memcpy.h

Remove local copies from each MPM file and use include file instead.
Might be better to also add util-memcpy.c rather than inlining it each time,
to get smaller code, since only seems to be used at initialization.
util-device: fix debug message

Reference to Pcap was not correct.
util-device: add function to avoid stat display

In the case of running mode like NFQ there is no need possibility
to compute the statistics as it is done in LiveDevice (drop and
checksum count are meaningless).

This patch adds a function that allow running mode to disable the
display of the counters at exit.
nfq: update running modes to hide device stats

This patch adds call to the function used to disable the display
of live device stats at exit.
nfq: update message displayed at exit

This patch updates the message displayed at exit to have something
more readable.
ipfw: update running modes to hide device stats

This patch adds call to the function used to disable the display
of live device stats at exit.
ipfw: improve exit message

This patch synchronizes the exit message with what is done in
NFQ capture mode.
ipfw: fix operator error in test

Fix warning spotted by clang on FreeBSD:

source-ipfw.c:241:49: warning: use of logical '||' with constant operand [-Wconstant-logical-operand]
        if (suricata_ctl_flags & (SURICATA_STOP || SURICATA_KILL)) {
                                                ^  ~~~~~~~~~~~~~
source-ipfw.c:241:49: note: use '|' for a bitwise operation
        if (suricata_ctl_flags & (SURICATA_STOP || SURICATA_KILL)) {
                                                ^~
                                                |

Use same logic as the one used in other capture mode.
Exit if BPF filter file is specified in IPS mode

This patch adds a check that was missing when specifying BPF filter
from a file. Suricata behavior should have been the same as when
BPF filter is specified on command line.