CRAN v0.4.0 submission

[grantmcdermott]

@vincentarelbundock @zeileis Just a HU that I plan to submit tinyplot v0.4.0 to CRAN tomorrow. I'll do my best to close out the following issues before then:

• Added elements are misaligned with facets #313 (will just have to take the form of better documentation for the moment)
• Smarter palette choice / recycling with many groups #352

Following Achim's neat solution in #403, it might also be possible to close #332 in a similar fashion. But I personally won't have time for that right now. Please feel free to take a crack if you're up for it.

[zeileis]

I already thought about adding a weights argument in #403 which would have been very straightforward in tinyplot.formula. But to do it properly in tinyplot.default and passing it on to the different types needs some more thought and testing. I guess it's better not to rush it and to do it with a little more time.

[grantmcdermott]

Submitted and all pre-checks passed. Just waiting on the revdep check now.