Add --version command line option.
Created a text file with version history.

Version 0.70 was initially used to imply that it's the beta version
of 1.0.  We'll want to change this section to 1.0 when it is
"released", and then we'll add the remaining issues that are fixed.
Added helpful print line.  Fixes #64.
Changed --version behavior and always print version on welcome screen.
Merge pull request #73 from ChodeGames/add_versioning

Add versioning.

This adds a version_history.txt file for a changelog, and displays the version number on each program run or when using the --version argument

Fixes #64