Make behaviour of convhulln() and delaunayn() consistent

[davidcsterratt]

In the current version of the package, the behaviour of convhulln() and delaunayn() differ:

• convhulln(): If the Qhull options n or FA are included in the options string, returns a list. Otherwise return a matrix.

• delaunayn(): If the full option is supplied return the areas and neighbours of each simplex.

It would be good to normalise the behaviour by removing the full option from delaunayn and only outputting a list when options such as Fa and Fn are specified. The only call to delaunayn with the full option is delaunayn(as.matrix(data), options="Fa Fn", full=T) in the restlos package.

Thus the proposal is:

• Make delaunayn respond to Fa and Fn options, outputting areas and neighbours
• Deprecate full, producing a WARNING

[davidcsterratt]

In 0.4.0 there is no message or warning; messages and then warnings will be added in future versions of geometry.