Proper CSV output for tools by escaping quotes

[tturocy]

The DiamondWare file format does not permit embedded quotes (") in text strings. However, occasionally one does slip through in files.

Chadwick takes the position that output is undefined for invalid input files, although attempts are made to muddle through as best as possible. In particular, the parser does tolerate such embedded quotes.

However, when there are strings with embedded quotes, these are output by the command-line tools with the quotes not escaped. As a result, the output files are not valid in standard CSV dialects.

It would be nice to do something sensible that resulted in clean CSV files in this case. The most straightforward solution would be to escape any embedded double-quotes on output. However this would require changing code in a substantial number of places. Further, one of the objectives of the command-line tools is that they are fast - any change to implement escaping of embedded double-quotes should not have a significant overhead that would slow output down in the case in which there aren't any - because after all there "shouldn't" be any in well-formatted input files.