Revist the names of DataFrame.arrange/2 and DataFrame.arrange_with/2

[billylanchantin]

There's been some discussion of renaming the arrange functions to sort. E.g. here:

• Add Series.sort_by and Series.sort_with #762 (comment)

This would align better with the Series function names. Plus, the arrange names come from R where they were chosen to avoid namespace conflicts. We don't have to worry about that here.

However, this would be a breaking change. This issue is to hash out that discussion.

[josevalim]

I am happy to roll with sort_by and sort_with. We should keep arrange and arrange_with around with @deprecated "foobar" annotations. They can simply delegate to the new sort_by and sort_with.

[cigrainger]

Yep agreed!

[billylanchantin]

Closed by: #777