Edit WebSubmit Function

This function sends an email to the referee of a document informing
him/her that the request for its approval has been withdrawn.

@param categ_file_withd: (string) - some document types are
       separated into different categories, each of which has its own
       referee(s).
       In such document types, it's necessary to know the document-
       type's category in order to choose the referee.
       This parameter provides a means by which the category information
       can be extracted from a file in the current submission's working
       directory. It should therefore be a filename.

@param categ_rnseek_withd: (string) - some document types are
       separated into different categories, each of which has its own
       referee(s).
       In such document types, it's necessary to know the document-
       type's category in order to choose the referee.
       This parameter provides a means by which the category information
       can be extracted from the document's reference number.
       It is infact a string that will be compiled into a regexp and
       an attempt will be made to match it agains the document's reference
       number starting from the left-most position.
       The only pre-requisite is that the segment in which the category is
       sought should be indicated with .
       Thus, an example might be as follows:
          ATL(-COM)?--.+
       This would allow "PHYS" in the following reference number to be
       recognised as the category:
          ATL-COM-PHYS-2008-001

@return: (string) - empty string.