Log Message:
Changes 2.10.0:
* Package help is now converted from Rd by the R-based converters
  that were first introduced in 2.9.0.
* HTML help is now generated dynamically using an HTTP server
  running in the R process and listening on the loopback interface.
* polygon(), pdf() and postscript() now have a parameter
  'fillOddEven' (default FALSE), which controls the mode used for
  polygon fills of self-intersecting shapes.
* New debugonce() function; further,
  getOption("deparse.max.lines") is now observed when debugging.
* plot() methods for "stepfun" and hence "ecdf" no longer plot
  points by default for n >= 1000.
* [g]sub(*, perl=TRUE) now also supports '\E' in order to *end*
  \U and \L case changes, thanks to a patch from Bill Dunlap.
* factor(), `levels<-`(), etc, now ensure that the resulting factor
  levels are unique (as was always the implied intention).  Factors
  with duplicated levels are still constructible by low-level means,
  but are now declared illegal.
* New print() (S3) method for class "function", also used for
  auto-printing.  Further, .Primitive functions now print and
  auto-print identically.
* The print() and toLatex() methods for class "sessionInfo" now
  show the locale in a nicer format and have arguments to
  suppress locale information.
* In addition to previously only round(), there are other 'Math'
  group (S3) methods for 'difftime', such as floor(), signif(), abs(), etc.
* For completeness, old.packages() and available.packages() allow
  'type' to be specified (you could always specify 'available'
  or 'contriburl').
* More...