Solution: Install CMake config in arch-dependent LIBDIR/cmake

Using "share/cmake/${PROJECT_NAME}" as DESTINATION for installing
ZeroMQConfig.cmake et al works for arch-independent configs, but
is wrong for multiarch. The configs for each version of the
library should be stored below the arch-dependent LIBDIR, using
the GNUInstallDirs ${CMAKE_INSTALL_LIBDIR} variable.
Signed-off-by: FeRD (Frank Dana) <ferdnyc@gmail.com>

Refactor protocol literals into constants

Some ifdefs in condition checking may cause problem in some compiler or
static analyzers. When PGM and NORM both are disabled, some condition
will be derived as false || false.

Solution: Splitted condition checking for every ifdef conditions

Conditinoal compile for OPENPGM and NORM is mixed.
Also found few codes which needs conditional compile but not applied.

Solution: Apply conditional compile preprocessors

Solution: replace into named constants

Optimizing gitignore files

Solution: optimize gitigore using patterns
 *  Categorize ignoring lists
 *  Use pattern to remove similar lists
 *  Marked source files to be tracked

Problem: msg_t functions do not respect coding style

Solution: fix them

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News out of date, formatting not clean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