Merge branch 'jh/simple-ipc-sans-pthread'

The "simple-ipc" did not compile without pthreads support, but the
build procedure was not properly account for it.

* jh/simple-ipc-sans-pthread:
  simple-ipc: correct ifdefs when NO_PTHREADS is defined

diff --cc Makefile
Simple merge

diff --cc contrib/buildsystems/CMakeLists.txt
Simple merge