The %{PR} tag is introduced for this. It resets all colors as well as
the activation of the underline and overline and font.
This has become necessary because we don't track what raw tags a user
injects into the formatting string and otherwise their raw tags could
bleed through.
This doesn't touch action tags because even before raw action tags
weren't being tracked. Action tags also have the requirement that they
have to be used in pairs, so closing them prematurely could break things
(for example with click actions for the entire bar)
This removes the spacing tinkering when parsing format specs.
The following example uses the old behavoir:
format-test = <label-foo> <label-bar>
format-breaks = <label-foo><label-bar>/<bar-test>
`format-test` would replace all occurences of ' ' with the
a space string with defined `spacing` as its width. `format-breaks` would
not validate as the tags where split with ' ' as delimiter.
All that nonsense has been removed and each tag is extracted as is.
The `spacing` parameter can still be used to apply N extra whitespaces
between the tags, but it is now 0 by default.
