Documentation polish (LICENSE/README/requirements) + test import cleanup

[peter-lawrey]

This PR updates project documentation for clarity and AsciiDoc correctness, and removes unused imports in a test. There are no functional code changes.

What’s changed

LICENSE.adoc

• Soft-wrapped long lines for readability.
• Kept license text unchanged; formatting only.

README.adoc

• AsciiDoc style fixes:

  • Consistent [caption="",link=...] syntax for badges.
  • Unified paragraphs and bullet formatting; reduced line-length and improved wrapping.
  • Standardized source blocks to [source,java], added section titles (e.g., .In Java 7 or 8).
  • Converted raw URLs to link: where appropriate.
  • Clarified and consolidated OS support notes and behavioral details.

• Improved explanations on:

  • OS-specific feature differences (Linux/Windows/macOS/Solaris).
  • JNA dependency/version implications and GLIBC note.
  • CPU layout detection and affinity mask usage.
  • Examples for acquiring locks, core reservation, and strategy control.
  • Lock file location and debugging output.
  • AffinityThreadFactory usage.

affinity/src/main/adoc/requirements.adoc

• Simplified header (kept :toc:; removed author/date/version/sectnums).
• Converted glossary to description list format for readability (e.g., CPU :: Central Processing Unit).
• Reflowed and wrapped paragraphs for consistency.
• Switched references to link: syntax; tightened wording.
• Minor content clarity updates without changing intent (cross-platform support, JNA/JNI notes, API goals, NFR details).

affinity/src/test/java/net/openhft/affinity/impl/PosixJNAAffinityTest.java

• Removed unused imports (Assume, assumeFalse).
• No behavior change.

Motivation

• Improve documentation consistency, readability, and AsciiDoc correctness.
• Reduce noise in tests by removing unused imports.

Impact

• Runtime behavior: None.
• Public API: None.
• Tests: Should continue to pass; only import cleanup.