nsIUnicharLineInputStream Interface

 Read a single line from the stream, where a line is a 
 possibly zero length sequence of characters terminated by a
 CR, LF, CRLF, LFCR, or eof.
 The line terminator is not returned.
 @retval false
         End of file. This line is the last line of the file
         (aLine is valid).
 @retval true
         The file contains further lines.
 @note Do not mix readLine with other read functions.
       Doing so can cause various problems and is not supported.