Add initial LICENSE

[gdicker1]

Provides initial legal information for the publication and use of the EarthWorks Modeling System.

[gdicker1]

Please let me know what you think of this @areanddee @sherimickelson. I made some formatting edits so that it will read well as a plain text document. Some of these include:

• Limiting to lines to 80 columns
• Editing/adjusting the table of sub-licenses
• Converting the footnotes to be more like endnotes in a Markdown style.

[areanddee]

Looks great. Thanks for reformatting.

[areanddee]

Provides initial legal information for the publication and use of the EarthWorks Modeling System.