grates 0.3.0

New functions

Conversion functions now preserve names.
Bug fixes for cast functions operating on objects of the same class but with different attributes.

This is a breaking release that changes the underlying implementations of the different grate constructors and associated scales for ggplot2. There has also been some renaming of function arguments to bring greater consistency across packages.
We now make more use of the high level API introduced by the clock package for working with R’s date and date-time types.