Option to set both input and output delimiter

[cweiske]

When using csvfilter as tool to filter data of one tool before passing it to another tool, input and output separator characters are mostly required to be the same.

Currently I have to specify csvfilter -d ";" --out-delimiter ";"which is long to write.

Having an option to set the output delimiter to the same value as the input separator would be nice, e.g.

csvfilter -ed ";"

(e for "equal"). This would also play nice with #10.