1 - Changed log level names, adding an 'L' in front of them,
    this avoids name clashes with some windows macros (sigh)
    Sorry for any inconvenience, but users must update code.

2 - added line buffering, this allows to concatenate output on
    a single log line with operator <<, line termination should
    be indicated with "\n" as usual.
    Current line is also terminated by changing active log level.

3 - Added a small console app sample

4 - Updated documentation because of changes in point 1