Update license

[menon-karthik]

Current situation

Closes #164

The current license is not an approved open-source initiative license. This makes it ambiguous in the general open-source landscape, such as for publication in Journal of Open Source software. This issue was raised during the JOSS review. The decision was therefore made to change the license for the repository to the BSD-3 license.

Note: I tried changing LICENSE.txt to LICENSE.md but that is not compatible with cpack. It should still be detected by GitHub according to this page.

Release Notes

• Updated license to BSD-3
• Removed long license text in all source files and replaced with shorter version mentioned by @mrp089 in Simplify license definition #164

Documentation

N/A

Testing

N/A

Code of Conduct & Contributing Guidelines

• I agree to follow the Code of Conduct and Contributing Guidelines.

[mrp089]

Thanks, @menon-karthik! The license name currently doesn't show up on the side bar ("About") or on top of the license file. Hopefully, that will appear after the merge. If not, we might have to try these manual steps.

[mrp089]

Looks great, no more work needed!