zeromq/czmqpp — pull request #30 by evoskuil (2014-11-02 11:26:46+00:00)
Title: Build warns and fails in configure on clang/yosemite.

Flags weren't checked and `-fvisibility=internal` caused failure on OSX.
Early positioning of `AC_USE_SYSTEM_EXTENSIONS` caused configure warning.
Fix above, add comments, set tools prereq.