Problem: SELFTEST_DIR declarations pollutes manual pages
Problem: SELFTEST_DIR declarations pollutes manual pages

Solution: make the documentation shorter, declare them before each selftest
method, convert to macros, so no dynamic string allocation or different
declaration for C and C++ are needed.

paddor/zproject,paddor/zproject,zeromq/zproject,zeromq/zproject,zeromq/zproject,paddor/zproject