Data names override default R functions

[MikeLydeamore]

There are a few named objects in the package datasets that are overwriting default R objects.

In Smoking: c and pi override the function and constant.
In Vaccine, c overrides the concatenate function.

In both cases, the bracketing means that the function and the dataset are accessible at the same time, but I could imagine an edge case (probably in do.call) that would cause some unexpected behaviour.

Could these be renamed so that if the data is loaded there can't be an accidental mixup?

openjournals/joss-reviews#4206