Updating copyrights.
Merge pull request #1087 from rapzo/dev

Updating copyrights.
Fix examples in headers() docblock.
Do not return compiled headers when setting header.

Benchmarks show:
- reduction of overall call count (previously 801, now 750)
- 1,120 bytes less max peak mem (now 2,746,952 bytes)
Refactoring Message::headers().
Optimizing conditional check for performance.
Optimize HTTP header parsing.
Noting that action request normalizes headers.
Mini-refactor action request scheme assignment.
Optimize request configuration.