* Update License header for all source files
- Add Apache 2.0 header to source files that did not have one.
- Update all existing headers dated to 2019 to be 2020
- Remove comma from License header to comply with the Apache 2.0
guidelines.
* Update Copyright notice
Use the standard Copyright notices outlined by the
[CNCF](https://github.com/cncf/foundation/blob/master/copyright-notices.md#copyright-notices)
* Add comments on needed filed alignment
Add comment about alignment requirements to all struct fields who's
values are passed to 64-bit atomic operations.
Update any struct's field ordering if one or more of those fields has
alignment requirements to support 64-bit atomic operations.
* Add 64-bit alignment tests
Most `struct` that have field alignment requirements are now statically
validated prior to testing. The only `struct`s not validated that have
these requirements are ones defined in tests themselves where multiple
`TestMain` functions would be needed to test them. Given the fields are
already identified with comments specifying the alignment requirements
and they are in the test themselves, this seems like an OK omission.
Co-authored-by: Liz Fong-Jones <elizabeth@ctyalcove.org>
