Add UDP transport to related docs

* UDP is mentioned as available transport, and it also supports
  wildcard addresses, but not mentioned
* zmq_unbind(7) also mentions about wild-card endpoint in zmq_bind(3)

Solution: add udp in wildcard address related docs

zmq_bind(3) and zmq_connect(3) does not mention UDP as available
transport types.

Solution: add udp mentioning line for related docs

Problem: building on OS X may failed

Solution: Add troubleshooting guidelines to resolve

(Relicensing statement added)

* ip_resolver_t: adding virtual descructor to silence C++-warning -Wnon-virtual-dtor

* adding my relicense

News out of date, formatting not clean

Solution: run make clang-format-diff

Solution: update it

Solution: add it

* add option to stop trying to reconnect on ECONNREFUSED

Fix unused-variable warning in perf/proxy_thr.cpp

Add relicense grant by Laszlo Boszormenyi (GCS)

Android build helper improvement + fix for prefix dir

Solution: Add usage and default value to README

Solution: Migrate the properties and the selection for the correct env
and abi to the helper. There's no need for the user to specify them.

Solution: Use pwd only a default value

Improve android build handling

Solution: Re-factor them to look like usual tables

Solution: Modify the build scripts so the user can specify the platform
for which to build, e.g. `./build.sh arm`. This approach originally
significantly reduces the parameters which have to be set before running
the script.

Further the build process is documented in a README now.

Add grant by ninoles

Received via email, message-id:

ed4de883-640b-bf7e-ac56-911e117b649e@tzone.org

problem: zeromq doesn't has a thread-safe peer to peer socket

Solution: a new socket type, called PEER. Very similar to SERVER, but can only connect to other PEERs. Also a new zmq_connect_peer method, that connect and return a routing-id in thread-safe and atomic operation

problem: maximum size of group doesn't match the RFC maximum size

Implement ZMTP 3.1 subscribe/cancel via commands

websocket problems

Solution: return after the fallback

fixes #3809

Grant from KLNikita

Received via email, message-id:
81ce91c8-df40-13c2-7abf-6f648d0b123f@elyzion.net

solution: if msg is not shared or constant, mask the message in place

Grant by asafkahlon