Add ability to comment on a prototype

[dlabaj]

Add the ability to add comments to a prototype. The comments should be added to generate github issues upon commenting. If a user close a comment the github issue should be closed as well. An example npm package is available here https://www.npmjs.com/package/hale-commenting-system. The code for this prototype should be harden and integrated into the cli.

[dlabaj]

Code for this can be found here:

• https://github.com/JustinXHale/pfseed-commenting-system
• http://npmjs.com/package/hale-commenting-system?activeTab=code