Added <br> support

This version add the conversion of
into a new line.

Improved README and fixed a notice

The $id protected member wasn't declared. Fixed.
The README has been improved.

Removed the lowercase from src conversion

The code doesn't longer perform lowercase of the image src attribute. Thanks chellem for the patch.

Improved documentation

Documentation uses javadoc style. Updated Doxyfile to the last version, removed all the warnings.

1.1

HTMLConverter doesn't strtolower() the href anymore on replaceLinks().

1.0

added badges