log4cpp 1.1.6 released

CMake support is enhanced. Building examples is enabled via the CMake's LOG4CPP_BUILD_EXAMPLES option. CMake usage examples are provided for both scenarios: importing a CMake-installed log4cpp library and using log4cpp as a CMake subproject.
Emulate autotools behaviour when building via CMake and generate include/log4cpp/config.h from Autotools-style config.h.in
Add test build support using CTest
Add formatted and streaming log4cpp macros with compile-time stripping
vsnprintf: Use va_copy for C+11 and later; use __va_copy for GCC pre-C++11; fallback to simple copy
Native project files are archived to prevent MS VS from mixing old project files with CMake builds