Dockly doesn't display well in a terminal using light colouring.

according to @1wilkens in #390 our current copy to clipboard binaries may not cover wayland (correct me if I am wrong).

maybe we can use this opportunity to cleanup the support for multiple fallback programs for running copy to clipboard:

• use which on all platforms
• have a list of platforms specific programs
• try them all before erroring out

Balance sheet column headings should be the column's end date:

Balance Sheet 2020-07-03

                                      ||                                   2020-07-03
======================================++==============================================

But in the HTML output, it seems to be a date range instead: