Point-range plots with `type="pointrange"`

[vincentarelbundock]

Partially fulfils Issue #25

[grantmcdermott]

Dig it. Lmk when it's ready for review.

Fwiw I don't know why the density plot tests are failing in the Ubuntu-dev CI run. I observed the same behaviour in #34 but haven't investigated properly yet.

[vincentarelbundock]

Cool. I added a NEWS item and think this is ready for review. Happy to make changes, of course.

I don't know about the error. I see this in R-devel NEWS, but don't know if it can explain:

‘density()’ more consistently computes grid values for the FFT based convolution, following Robert Schlicht's analysis and proposal in PR#18337, correcting density values typically by a factor of about 0.999. Optional ‘old.coords=TRUE’ provides back compatibility.

[grantmcdermott]

Very stoked to have this added. Thanks Vincent.

(Next step: ribbons!)

[vincentarelbundock]

Yay!

[zeileis]

Very cool!