A few fixes and rewrites

-> Added Filename variable to log_config.ini
-> Moved Benchmark and time conversion funcs inside el::utils::time
-> Time conversion functions are now inline functions, instead of macros
-> Added CERR and COUT macros to encapsulate in a single ( ) the error
or debug info
-> Typedef for response of initialization or (re)configuration
-> long to auto in file_size to avoid warnings
-> Removed smart_mutex class: gives problems, lots of problems
-> Started constructor for LogConfig
-> Added generic function in Writer class to automatically lock and
unlock the mutex while data is pushed into the stream
> bool Ready now checks if log_config is initialized
-> resp Initialize now returns a message of error in case the log_config
is already initialized
-> resp addLogConfig returns a message of error in case the log config
is not initialized
-> Changed throw to CERR when logging to avoid crash of application, the
logging system is initialized with default info and a writer is returned