Harmonizing csv commands

All the csv commands now support setting a character delimiter. This allows us to use the csv commands with other delimiters (e.g. colon or pipe delimited files). Unless noted the delimiter affects both input and output.

Here's an example of using csvfind one a pipe delimited file called file.txt looking for "Fred" in the second
column.

    csvfind -i file.txt -d '|' -col 2 "Fred"