Fix app-layer-protocol FP on multi TX flow

In case of multiple transactions, the stored AMATCH list would not have
been reset, but it would still be reconsidered. Even though none would
match, the engine would still conclude that the rule matched.
detect state: remove alproto check for AMATCH

Not all AMATCHes set a alproto.
detect state: fix indent

AMATCH block was indented too far.
TLS: register patterns for tls-alerts

Register patterns for when server has an alert as the first message.
icmpv6: add multicast types

Only add them to check if the code is 0 and to make sure the default
case doesn't set an 'unknown type' event.
ipv6: add support for PAD1

Support PAD1 in IPv6 HOP options header and DST options header.
tls: no event on 'new session ticket' in handshake

Don't set an event on encountering a 'new session ticket' (4) record
in the TLS handshake.
Change configure to allow statically linking libpcre.

Statically linking libpcre requires using -lpthread, which is added
when building Suricata, but not while checking for libpcre in configure.
Force pidfile creation of --pidfile.

A pidfile can be useful when not in daemon mode, for example
when running under a process supervisor.