Added options for file names.

* Options for file names allow specification of the columns of interest
  in files (keys, scores, labels).
* Options are parsed and checked but are currently ignored during
  processing.  They will not work until they are incorporated into
  improved file processing.
* Added function to parse and handle file options.  Parsing is via
  regular expressions.
* Added FileArgument which wraps a file name and its options.
* Wrote help for file options with examples.
* Updated copyright year in about string.
Created code for projecting and joining CSVs.

* Created code for projecting and (natural/inner) merge joining CSVs.
* Created tests for new CSV processing code.
* Updated makefile with dependencies for new files.
Changed sorting code to work with Javas prior to 8.
Documented CsvProcessing.

* Removed old import.
Implemented joining of input CSVs in Main.

* Added Main API functions for building curves from CSVs in various
  ways.
* Added ability for Main to join input CSVs by reworking core processing
  to use above new API.
* Created tests for Main API.
* Changed iterators to iterables.
* Updated dependencies in makefile, including adding a
  previously-missing dependency.
* Fixed a few spelling and cosmetic things with comments, wrapping.
* Removed all old/obsolete code.  Unfortunately, this makes the diff
  messy.
Streamlined reading CSV inputs in Main.

* Created function for reading CSV input from a named file or the given
  input as specified.
* Eliminated repeated file input code.
* Removed function for opening a named file or using the given input.
* Removed function for checking empty input.