Support size and linetype in geom_hex (#2488)

[mikmart]

Fixes #2488: size (and additionally linetype) can now be used in geom_hex() to control the bordering lines of the hexagons.

ggplot(diamonds, aes(carat, price)) +
  geom_hex(col = "red", size = 2)

[hadley]

Can you please add a bullet to NEWS? It should briefly describe the change and end with (@yourname, #issuenumber).

[hadley]

Also can you please use Fixes #2488 — that specific wording will cause the related issue to be automatically closed when this PR is merged.

[mikmart]

Sure! I've updated the PR comment to use Fixes, and also added the NEWS bullet (hopefully correctly).

This is my first PR, and I'm a bit new to Git, so hopefully the NEWS bullet addition is OK; I had some trouble with incorporating all the other commits that happened since I opened the PR, (tried to rebase branch with upstream, pull origin, and then push; but that ended up with 30 commits in this branch somehow -- forced a reset on that), so I ended up just doing a deliberate merge conflict to be able to add the bullet without too much of a mess.

[hadley]

Looks good, thanks!

[lock]

This old issue has been automatically locked. If you believe you have found a related problem, please file a new issue (with reprex) and link to this issue. https://reprex.tidyverse.org/