[WIP] Streamlog thread safe

Created by: rete

BEGINRELEASENOTES

• Re-implemented streamlog library with new features and thread safety
• Thread safety:
  • Each logger can be thread safe depending on creation parameter (enable/disable thread safety)
  • Global logger thread safety fixed at library compilation time using the cmake option -DSTREAMLOG_DEFAULT_LOGGER_TS=ON/OFF (default is ON)
• If thread safety parameter is used:
  • Logging from two threads in the same logger is thread safe
  • Changing any logger property (log level, name, formatter, ...) while logging in another thread is thread safe
• New features:
  • Possibility to format differently the log message output using the standard_formatter class (time, thread id, logger name and level)
  • Possibility to sub class the formatter class to provide custom formatting
  • Possibility to log in different output streams (console, file, etc...) using the same logger by using sinks
  • Builtin sinks:
    • console (std::cout)
    • colored console (std::cout)
    • simple file (std::ofstream)
    • multi thread files: one log file per logging thread
• Added Readme.md file describing the new API and features
• Redesigned such that any program using streamlog_out(LEVEL) pre-processor like macros is backward compatible
• Breaks backward compatibility regarding streamlog initialization. Example: initialization in Marlin framework
• Added simple example and multi threading example

ENDRELEASENOTES

The logger thread safety has been verified using valgrind (helgrind) and by running the multi threading example.

TODO:

• Verify backward compatibility assumption