roxygen2 3.0.0

Roxygen2 now fully supports S4 and RC (reference classes) - you should no
longer need to manually add @alias or @usage tags for S4 classes, methods
and generics, or for RC classes.

• The default usage definitions are much better, generating the correct
  usage for data sets (#122), S3 methods (without additional @method tag),
  S4 generics, S4 methods, and for replacement (#119) and infix functions.
  Backslashes in function arguments in are correctly escaped. Usage statements
  also use a more sophisticated line wrapping algorithm so that they should
  cause fewer problems with the R CMD check line limit. (#89, #125).
• S4 classes, S4 methods, and RC classes are given better default topics,
  and the file names corresponding to those topics are shorter.
• S4 methods will automatically inherit parameter documentation from their
  generic.
• @slot name description allows you to document the slots of a S4 class.

S3 support has also been improved: roxygen2 now figures out whether a function
is a S3 method or generic. (In the rare cases it does so incorrectly, use
@method to manually describe the generic and class associated with a method).
This means you can remove existing uses of @method, and can replace
@S3method with @export.

Roxygen now has support for package specific options through the Roxygen
field in the DESCRIPTION. The value of the field should be R code that
results in a list. Currently only wrap and roclet values are supported:

• Turn off Rd re-wrapping with adding Roxygen: list(wrap = FALSE)
• Change the default roclets by specifying
  Roxygen: list(roclets = c("collate", "rd"))

Roxygen 3.0 also includes a number of minor fixes and improvements:

• Infix functions are now escaped correctly in the NAMESPACE. (Thanks to
  @crowding, #111)
• roxygenise() now works more like devtools::document() and only ever works
  in the current directory. The arguments roxygen.dir, overwrite,
  copy.package and unlink.target have been deprecated due to potential
  data loss problems.
• The collate roclet is no longer a roclet: it processes R files using custom
  code (only statically, not dynamically) and is designed to be executed before
  the code is sourced. Run update_collate() to update the Collate directive
  based on @include tags - if there are none present, a collate directive
  will not be generated.
• @useDynLib now works with more possible specifications - if you include a
  comma in the tag value, the output will be passed as is. This means that
  @useDynLib mypackage, .registration = TRUE will now generate
  useDynLib(mypackage, .registration = TRUE) in the NAMESPACE. (#124)
• inst directory not created by default (#56).
• Explicitly depend on utils and methods packages to make roxygen
  compatible with Rscript (#72). Import digest package instead of
  depending on it.
• Always use C locale when sorting NAMESPACE file or tags in .Rd files.
  This ensures a consistent ordering across systems (#127).
• Templates with extension .r are supported on case-sensitive file systems
  (#115). Template variables now actually work (#160, thanks to @bronaugh).
• Suppress default aliases, format and usage with @aliases NULL,
  @format NULL and @usage NULL.