Author:  Mikhail Bulychev

Function:
      Portfolio exports values of bid/offer to a text file for instruments
      of the selected classes

How to use:

     Row quote_file="qoutes.txt" defines name of file to which the export must be performed.
     Contents of the file is cleared at the portfolio start.
     Row class_code_list="EQBR,EQBS,EQNL,EQNE" set a list of classes with securities to be exported
