bug#70832: 30.0.50; repunctuate-sentences should respect sentence-end-double-space

[Juri Linkov]

>> In paragraphs.el there is a variable  'sentence-end-doulbe-space` that 
>> indicates where we should expect
>> sentences to end with one or two spaces after a period. In the same file a 
>> command is provided called
>> "repunctuate-sentences", which steadfastly ignores the value of this 
>> variable and expands all single-space
>> endings to two-space endings.
>>
>> It strikes me that the naming of this command does not imply that it will 
>> insist on two-spaces (even if the docs
>> say so), and it would be more sensible and offer more utility for it to 
>> respect the users wishes.  As the variable
>> default to `t, changing this function would have zero impact on the default 
>> behaviour.
>
> Patches to allow repunctuate-sentences heed the value of
> sentence-end-double-space are welcome.

The purpose of repunctuate-sentences is
to put two spaces at the end of sentences.
What should it do when sentence-end-double-space is nil?