Update to 3.6.1

Upstream changes:
CHANGES IN R 3.6.1:

  INSTALLATION on a UNIX-ALIKE:

    * The default detection of the shell variable libNN is overridden
      for derivatives of Debian Linux, some of which have started to
      have a /usr/lib64 directory.  (E.g. Ubuntu 19.04.)  As before, it
      can be specified in config.site.

  UTILITIES:

    * R CMD config knows the values of AR and RANLIB, often set for LTO
      builds.

  DEPRECATED AND DEFUNCT:

    * The use of a character vector with .Fortran() is formally
      deprecated and gives a non-portability warning.  (It has long
      been strongly discouraged in 'Writing R Extensions'.)

  BUG FIXES:

    * On Windows, GUI package installation via menuInstallPkgs() works
      again, thanks to Len Weil's and Duncan Murdoch's PR#17556.

    * R CMD check on data() fixing PR#17558 thanks to Duncan Murdoch.

    * quasi(*, variance = list(..)) now works more efficiently, and
      should work in all cases fixing PR#17560.  Further, quasi(var =
      mu(1-mu)) and quasi(var = "mu ^ 3") now work, and quasi(variance
      = "log(mu)") now gives a correct error message.

    * Creation of lazy loading database during package installation is
      again robust to Rprofile changing the current working directory
      (PR#17559).

    * boxplot(y ~ f, horizontal=TRUE) now produces correct x- and
      y-labels.

    * rbind.data.frame() allows to keep <NA> levels from factor columns
      (PR#17562) via new option factor.exclude.

      Additionally, it works in one more case with matrix-columns which
      had been reported on 2017-01-16 by Krzysztof Banas.

    * Correct messaging in C++ pragma checks in tools code for R CMD
      check, fixing PR#17566 thanks to Xavier Robin.

    * print()ing and auto-printing no longer differs for functions with
      a user defined print.function, thanks to Bill Dunlap's report.

    * On Windows, writeClipboard(.., format = <n>) now does correctly
      pass format to the underlying C code, thanks to a bug report
      (with patch) by Jenny Bryan.

    * as.data.frame() treats 1D arrays the same as vectors, PR#17570.

    * Improvements in smoothEnds(x, *) working with NAs (towards
      runmed() working in that case, in the next version of R).

    * vcov(glm(<quasi>), dispersion = *) works correctly again, fixing
      PR#17571 thanks to Pavel Krivitsky.

    * R CMD INSTALL of binary packages on Windows now works also with
      per-directory locking.

    * R CMD INSTALL and install.packages() on Windows are now more
      robust against a locked file in an earlier installation of the
      package to be installed.  The default value of option
      install.lock on Windows has been changed to TRUE.

    * On Unix alikes (when readline is active), only expand tilde (~)
      file names starting with a tilde, instead of almost all tildes.

    * In R documentation (*.Rd) files, \item [..] is no longer treated
      specially when rendered in LaTeX and hence pdf, but rather shows
      the brackets in all cases.


(wen)