Solution: update to 2016

This reduces chances of race between writer deactivation and activation.

Reader sends activation command to writer when number or messages is
multiple of LWM. In situation with high throughput (millions of messages
per second) and correspondingly large HWM (e.g. 10M) the difference
between HWM needs to be large enough - so that activation command is
received before pipe becomes full.

Solution: Move the macros to a private header.

Solution: Convert to spaces and remove trailing whitespace in these files.

Of course people still "can" distributed the sources under the
LGPLv3. However we provide COPYING.LESSER with additional grants.

Solution: specify these grants in the header of each source file.

Not adjusting the sent message count may lead to situation when SUB
socket does not forward its subscriptions.

Solution: update for 2015

Fixes #1320

Revert "linking fd to pipe identity via socket option"

This reverts commit fe3e8c5c.

Conflicts:
	include/zmq.h
	src/pipe.hpp
	src/session_base.cpp

Fixes #872

Fixes LIBZMQ-584

The get_credential () member function returns
credential for the last peer we received message for.
The idea is that this function is used to implement user-level API.

These were exposed to users, but have subsequently been removed as
sockopts. They are currently only being used by ZAP, so I've moved it to
a simpl function call (actually it's only used in one case even in that,
so there may be a further simplification possible there).

ZMQ_CONFLATE option is passed to pipepair() which creates a usual
ypipe_t or ypipe_conflate_t and plugs it into pipe_t under a common
abstract base.

Copyrights had become ads for Sustrik's corporate sponsors, going against the original
agreement to share copyrights with the community (that agreement was: one line stating
iMatix copyright + one reference to AUTHORS file). The proliferation of corporate ads
is also unfair to the many individual authors. I've removed ALL corporate title from
the source files so the copyright statements can now be centralized in AUTHORS and
source files can be properly updated on an annual basis.

Code as stands breaks shutdown process. It was a bugfix by Arthur to a
bad line which was testing for an impossible state - but afaics we do
actually want to flush in those states. It is possible I am wrong on
that though - if there are any shutdown issues introduced aroudn this
commit I would suggest further investigation around this flushing
behavior.