Updated informational commands to output and quit.

* Updated about and version informational commands to write to standard
  output and immediately quit.
* Changed version command to output a short, machine-parseable
  name-version format message rather than be an alias for the about
  command.
Added MetaInfo class.

* MetaInfo contains version and other meta information so that it is
  accessible programmatically and to external tools.
* Updated makefile to get version information from MetaInfo class.
* Reworked about and version commands to use meta information.
* Updated about message to include license information.
* Updated help.
Removed license command line option.