Fix compilation on systems without O_CLOEXEC. This affects, e.g., Solaris 10. GitHub issue #326. (Patch by Jiangrz).

Provide log4cplus::deinitialize() to make the API symmetric (log4cplus::initialize() already exists) and to allow de-/initialization without log4cplus::Initializer instance. GitHub issue #340.

Deal with register keyword being generated in SWIG based bindings. The keyword is unused and reserved in C++17. Remove use of std::unary_function, it was removed in C++17.

Add ability to define new log levels using C API. Add reconfiguration API. (Jens Rehsack)

Add NDCMatchFilter and MDCMatchFilter. (Franck)