suggested by PEP 291.

This is a conservative version of SF patch 504889.  It uses the log
module instead of calling print in various places, and it ignores the
verbose argument passed to many functions and set as an attribute on
some objects.  Instead, it uses the verbosity set on the logger via
the command line.

The log module is now preferred over announce() and warn() methods
that exist only for backwards compatibility.

XXX This checkin changes a lot of modules that have no test suite and
aren't exercised by the Python build process.  It will need
substantial testing.

  installations are present, by always unlinking the destination file
  before copying to it.  Without the unlink(), the copied file remains
  owned by its previous UID, causing the subsequent chmod() to fail.

Bugfix candidate, though it may cause changes on platforms where
  file ownership behaves differently.

do it back in copy_file() (not at module level).

this will please everyone (as if that's possible).

Standardize use of whitespace on function calls.

than a boolean indicating whether it did the copy.

destination path, otherwise show just the directory.

  - file_util.py: operations on single files
  - dir_util.py: operations on whole directories or directory trees
  - dep_util.py: simple timestamp-based dependency analysis
  - archive_util.py: creation of archive (tar, zip, ...) files
The functions left in util.py are miscellany that don't fit in any of the
new files.