Solution: update to 2016

Make it ready to enable ipv6 for AIX or HP/UX

Solution: Move the macros to a private header.

See #1220 recent comments. This change is untested yet seems
safe.

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.

Solution: update for 2015

Fixes #1320

This reverts commit 78a7b469.

This syntax is undocumented and has no known meaning. It was in libzmq
since 3.x.

Solution: remove this code.

Since https://github.com/zeromq/libzmq/commit/350a1a, TCP addresses
get resolved asynchronously, so zmq_connect no longer returned an
error on incorrect addresses.

This is troublesome since we rely on some error checking to catch
blatant errors.

Solution add some upfront syntax checking that catches at least the
obvious kinds of errors (invalid characters, wrong or missing port
number).

Few examples:
tcp:://192.168.0.4:55555;192.168.0.254:1234
tcp:://192.168.0.4:0;192.168.0.254:1234
tcp:://eth2:55555;192.168.0.254:1234

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.

Compiling without warnings is a good goal, because it makes
new warnings (which probably indicate bugs) stand out rather
than getting lost in the spam.

My fixes fall into two categories:

    - Adding (void) casts of unused parameters, where their
      unusedness seems like a TODO (or in some cases a bug?).

    - Removing parameter names altogether, where the function
      is clearly a stub that will never use its parameters.

Should be no change in behavior.

Static analysis says:
src\tcp_address.cpp(297): error V595: The 'res' pointer was utilized before it was verified against nullptr. Check lines: 297, 301.
src\tcp_address.cpp(603): error V106: Implicit type conversion third argument 'full_bytes' of function 'memcmp' to memsize type.
src\tcp_address.cpp(603): error V526: The 'memcmp' function returns 0 if corresponding buffers are equal. Consider examining the condition for mistakes.

In fact the use of "memcmp" is correct, but the enclosing "if" isn't
necessary, and the compiler is happier if "full_bytes" is a size_t.

- Android crosscompiler shows a warning about two signed/unsigned checks
  on compilation, this patch adds casts to avoid this, so zmq3.x can
  compile on it.

fix bug in zmq::tcp_address_t::resolve_interface() where all resolved interface ip's overwrited by 0.0.0.0

Assign arbitrary number of filters that will be applied for each new TCP transport
connection on a listening socket.
If no filters applied, then TCP transport allows connections from any ip.
If at least one filter is applied then new connection source ip should be matched.
To clear all filters call zmq_setsockopt(socket, ZMQ_TCP_ACCEPT_FILTER, NULL, 0).
Filter is a null-terminated string with ipv6 or ipv4 CIDR.

For example:
localhost
127.0.0.1
mail.ru/24
::1
::1/128
3ffe:1::
3ffe:1::/56

Returns -1 if the filter couldn't be assigned(format error or ipv6 filter with ZMQ_IPV4ONLY set)

P.S.
The only thing that worries me is that I had to re-enable 'default assign by reference constructor/operator'
for 'tcp_address_t' (and for my inherited class tcp_address_mask_t) to store it in std::vector in 'options_t'...

This still rejects 00 as port number.