initial import of nget-0.27

initial import of nget-0.27
Based upon the package provided by Joel CARNAT in PR pkg/26134

nget is a command line nntp file grabber.
It automatically pieces together multipart postings for easy
retrieval, even substituting parts from multiple servers and
newsgroups. Handles disconnects gracefully, resuming after the
last part succesfully downloaded.

features:
  * Automatic multi-part post joining
  * Automatic binary decoding (using uulib)
  * Caches header data for quick access
  * Full multi-server support, transparently joining parts
    from different servers
  * Full multi-group support, transparently joining parts from
    multiple newsgroups
  * Automatic retries on network errors
  * Resumes after the last part successfully downloaded
  * Dupe file detection to avoid unneeded downloads
  * Select what to retrieve based upon a regular expresson (-r),
    or even a more complex expression (-R) based upon any of the
    file's subject, author, lines, bytes, # of parts we have,
    # of parts req, date, age, messageid, and references.
  * Search for newsgroups based on their names and/or descriptions
  * Automatic handling of PAR and PAR2 files retrieves only as many
    recovery files as necessary to repair any missing/damaged files.