* \fn int init_pers(Prof * professor, int x, int y, int length, int width, int speed, char * path)
* \brief This function initialize the character : position of the professor's top left corner (x,y), size (length, width), speed and also the path to the character's image.
*
* \param [in] professor a pointer on the character
* \param [in] x the professor's abscissa
* \param [in] y the professor's ordinate
* \param [in] length the professor's length
* \param [in] width the professor's width
* \param [in] path the path to the professor's image