http: strip 'proxy' part of http_uri

Strip the 'proxy' parts from the normalized uri as inspected by http_uri,
urilen, pcre /U and others.

  In a request line like:
    GET http://suricata-ids.org/blah/ HTTP/1.1
  the normalized URI will now be:
    /blah/

This doesn't affect http_raw_uri. So matching the hostname, etc is still
possible through this keyword.

Additionally, a new per HTTP 'personality' option was added to change
this behavior: "uri-include-all":

  uri-include-all: <true|false>
    Include all parts of the URI. By default the
    'scheme', username/password, hostname and port
    are excluded. Setting this option to true adds
    all of them to the normalized uri as inspected
    by http_uri, urilen, pcre with /U and the other
    keywords that inspect the normalized uri.
    Note that this does not affect http_raw_uri.

So adding uri-include-all:true to all personalities in the yaml will
restore the old default behavior.

Ticket 1008.
Reduce the size of Packet structure

Share memory space for IPV4Vars and (IPV6Vars, IPV6ExtHdrs), since a
packet can only be either IPv4 or IPv6, but not both.

Share memory for TCPVars, UDPVars, ICMPV4Vars and ICMPV6Vars, since a
packet can only be only of these.

Then move other structure members around to remove holes reported by pahole.

This reduces the size of the Packet structure from 2944 bytes (46 cachelines)
down to 1976 (31 cachelines), a 33% reduction.
SSE 4.2 memcmp: don't read beyond var boundary

In the SSE 4.2 SCMemcmpLowercase implementation, there would be a
_mm_load_si128 of a 2 byte array. However, _mm_load_si128 loads
16 bytes, causing it to read beyond the var. I don't think this lead
to crashes, as it was a static var, but clangs ASAN complained about
it.
http: add meta-field-limit option

The meta-field-option allows for setting the hard limit of request
and response fields in HTTP. In requests this applies to the request
line and headers, not the body. In responses, this applies to the
response line and headers, not the body.

Libhtp uses a default limit of 18k. If this is reached an event is
raised.

Ticket 986.
flow: aligned flow balance structures (used by autofp) to CLS to reduce false sharing
build-info: add a nicer way of printing atomics support
Fix autofp flow queue handler optimization