RELICENSE: Received grant from Micromass UK Limited

RELICENCE: Phillip Mienk grant

Problem: no relicense grant from PNNL

Solution: add the one received by email

B671D81EAD34104986FFE7881B8036371ABEF4AF@EX10MBOX02.pnnl.gov

Problem: missing relicense statement from Prarrot

Solution: add the one received by email

Message-ID: <CAHPFjttticWbCuZ93r55gGRDBMxAgNn==4r70op4LnQNEJM23Q@mail.gmail.com>

Problem: missing relicensing statement from somdoron

Solution: add it

Relicense: Dylan Cali

Ref: #2376

Problem: non-linux build broken by last PR

Solution: ifdef it

Solution: name it ZMQapp instead of ZMQbg, as it's created by the
application

Solution: use LIBZMQ_UNUSED

Solution: do it and remove ifndef windows

Solution: start at 0

Solution: use / like the rest of the names

Solution: use the thread class function rather than one of the pthread
functions, and take into account the thread prefix context option

Solution:
1. Use optional name parameter in thread_t::start for operating
systems that have thread names.
2. Give start_thread() an optional name parameter for the
thread's name. If this parameter is set, it will be appended to "0MQ:".
If not set, "0MQ" will be used as the thread's name.
3. Give epoll the ability to name its thread. Then use this in
io_thread and reaper to name them.

Solution: add relicense agreement

RELICENSE: Arthur O'Dwyer grant

Add permission to relicense

Problem: missing relicensing statement from bluca

Solution: add it - I realised only now that I only submitted a
statement for the copyright owned by a previous employer, and not
my own.

* Problem: trie benchmarks count loop times instead of lookup calls

Solution: measure the time taken by each lookup call instead

Other changes:
- show average time taken and reduce other output
- show number of keys, queries and key size before running the benchmark
- use steady_clock as high_resolution_clock might not be steady
- increase size of query set to 1M

Use std::condition_variable_any, move configuration to build files

Solution: change into regular control flow condition

Solution: change variable type to size_t

Problem: test_security_curve build fails with Windows targeting 8 or newer due to duplicate definition of htonll

Solution: use custom implementation only on older Windows versions

Solution: move configuration to build definition

Solution: calculate from CMAKE_SYSTEM_VERSION

Problem: CMAKE_SYSTEM_VERSION might be newer than Windows SDK Version

Solution: limit _WIN32_WINNT value to Visual Studio default Windows SDK version

Problem: std::condition_variable can only be used with std::unique_lock<std::mutex>, leading to two mutexes used in condition_variable_t

Solution: use std::condition_variable_any instead

Problem: cannot monitor state of queues at runtime

Solution: add API and ZMQ_EVENT_PIPES_STATS event which generates 2
values, one for the egress and one for the ingress pipes respectively.
Refactor the events code to be able to send multiple values.

Solution: refactor code and add extra frame with value count before the
values in v2