Values that contained ": " would not be parsed correctly for copying to
the clipboard. If, for example, a password contained ": ", those
characters and any following them wouldn't be copied. This change allows
such passwords to be copied correctly.

Also include brief notices in the source files. Not a fan of the huge
blocks of text that the FSF recommends.

Get option extraction/parsing working both for STDIN and for calls to
`pass show`.

If no argument is passed to the executable or the first argument is "-",
options are read from STDIN. Otherwise, the first argument is passed to
`pass show`, the output of which is parsed as options.

Temporarily comment out code that deals with STDIN to get this feature
working. It complicated things to leave it in right now.

Given an argument that isn't "-" (STDIN), we pass that argument to `pass
show`. Users correctly get a password prompt from `pass`, and the output
from the command gets sent to the Passextract TUI for display in the
menu and copying.

Remove the duplication of these lines for the `j` and `k` commands by
extracting them to a function.

Make the title appear in white-on-black knockout text.

Use `_` for the default/general case. Do nothing in this case, just
continue looping.

Delete this line from the TUI display and adjust the real output lines
to be one line higher.