[LyX/master] use package parskip to separate paragraphs with vertical space (#4796)

[Richard Kimberly Heck]

On 6/29/20 3:02 AM, Jürgen Spitzmüller wrote:
> Am Sonntag, den 28.06.2020, 18:14 -0400 schrieb Richard Kimberly Heck:
>> On 6/28/20 12:50 PM, Jürgen Spitzmüller wrote:
>>> Am Sonntag, den 28.06.2020, 12:36 -0400 schrieb Richard Kimberly
>>> Heck:
>>>> If I'm reading this right, it just silently fails if parskip is
>>>> not
>>>> installed. Or am I missing something?
>>> Yes, right (it does not fail, it just does not separate
>>> paragraphs).
>>> But we can really assume parskip to be installed. It's a pretty
>>> standard package.
>> OK.
> Rethinking it, though, I think that it's better to issue an error if
> the package is not there (as we do elsewhere).
>
> I changed this.

My thought was just to do what we used to do before, and maybe issue a
warning. But if the package is that common, maybe it does not matter.

Riki