proposal - psql - possibility to redirect only tabular output

Hi

Now, the content of redirect output has two parts

1. tabular output
2. cmd tags

There is a problem with command tags, because it is specific kind of
information and can be nice if can be redirected to stdout every time like
\h output. There can be new psql variable like REDIRECTED_OUTPUT with
possibilities (all, tabular)

What do you think about this?

Pavel