Log Message:
cppzmq: added version 4.8.1

cppzmq is a C++ binding for libzmq. It has the following design goals:

* cppzmq maps the libzmq C API to C++ concepts. In particular:
  - it is type-safe (the libzmq C API exposes various class-like concepts as
    void*)
  - it provides exception-based error handling (the libzmq C API provides
    errno-based error handling)
  - it provides RAII-style classes that automate resource management (the
    libzmq C API requires the user to take care to free resources explicitly)

* cppzmq is a light-weight, header-only binding. You only need to include the
  header file zmq.hpp (and maybe zmq_addon.hpp) to use it.

* zmq.hpp is meant to contain direct mappings of the abstractions provided by
  the libzmq C API, while zmq_addon.hpp provides additional higher-level
  abstractions.