chars such as ', \', \ , etc. Fixed a bug when parsing the GET
   arguments. Added new RPN functions :
   - str_replace( a, b, c ) : replaces all occurences of b with c in a
   - addslashes( s ) : escapes all " and ' with a backslash
   - stripslashes( s ) :  the opposite
   - htmlspecialchars( s ) : replaces &"'<> with their &stuff; equivalent
   - realpath( s ) : returns an absolute file path (see realpath(3))
   And fixed a few memory leaks.