Allow any negative timeout value to set subscription auto-renewal; fix typo in authors file.
Make same changes to CXXFLAGS as to CFLAGS during configuration.
Can't have identifier named "interface" on Windows.

It is effectively a reserved keyword if Windows.h is included.
(cf. http://stackoverflow.com/questions/10675077/vs2008-c-interface-as-a-parameter-name-fails-to-compile)
Fix some includes so that testcpp works under Windows.
Fix includes and defines to make testcustomtransport compile under Windows.