IOSource reorg.

A bunch of infrastructure work to move IOSource, IOSourceRegistry (now
iosource::Manager) and PktSrc/PktDumper code into iosource/, and over
to a plugin structure.

Other IOSources aren't touched yet, they are still in src/*.

It compiles and does something with a small trace, but that's all I've
tested so far. There are quite certainly a number of problems left, as
well as various TODOs and cleanup; and nothing's cast in stone yet.

Will continue to work on this.
Fixing rebase relicts.
Merge branch 'topic/robin/dynamic-plugins-2.3' into topic/robin/pktsrc
A series of updates and tweaks to the new PktSrc interface.
Prototype of a netmap packet source.

TODO: Add userland BPF filtering so that our filters work.
MySQL analyzer
Split the types and attributes reference doc into two docs

Also moved them up in the index so that the more fundamental material
comes before the more advanced material in the table of contents.
change SSL log to contain a boolean flag signaling if a session was resumed
instead of the (usually not really that useful) session ID the client sent.
add information about server chosen protocol to ssl.log, if provided by alpn.

This is e.g. used to negotiate spdy or http/2
Get MySQL to compile and add basic v9 support.
Update baselines.
Add memleak and auth btests.
Whitespace/readability fixes.
Mark everything below 2048 bit as a weak key (Browsers will stop
accepting 1024 bits soon, so we can be of that opinion too).

Also - fix notice suppression. :/
update test baselines
Redo the response handling..
Add support for more commands, and support quit
Add a btest for the Wireshark sample MySQL PCAP
Merge remote-tracking branch 'origin/master' into topic/robin/pktsrc

Conflicts:
	configure
	src/CMakeLists.txt
	src/Net.cc
	src/PacketSort.cc
	src/PacketSort.h
	src/RemoteSerializer.cc
	src/Sessions.cc
	src/Sessions.h
Removing netmap, remaining pieces of the 2ndary path, and left-over
files of packet sorter.

Netmap will move to a plugin.