RFR: 8261366: Add discussion of IEEE 754 to BigDecimal [v3]

[Joe Darcy]

> Informative update to BigDecimal and related classes to latest IEEE 754 terminology, including a discussion of the similarities and differences of BigDecimal and IEEE 754 decimal arithmetic.
> 
> Once the wording is finalized, I'll reflow any modified paragraphs and update the copyright years, etc.

Joe Darcy has updated the pull request incrementally with one additional commit since the last revision:

  Reflow paragraphs and update copyrights.

-------------

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/2868/files
  - new: https://git.openjdk.java.net/jdk/pull/2868/files/a29d60fd..39c20d67

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=2868&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=2868&range=01-02

  Stats: 20 lines in 3 files changed: 2 ins; 0 del; 18 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2868.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2868/head:pull/2868

PR: https://git.openjdk.java.net/jdk/pull/2868