RFR: JDK-8285688: Add links to JEPs and JSRs to SourceVersion [v3]

[Joe Darcy]

> To provide more context to readers about the development of the language, add to the enum constants in SourceVersion @see links to the JEPs and JSRs that added features to a release.
> 
> (For now, have left out @see links to preview features.)

Joe Darcy has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains four additional commits since the last revision:

 - Use https rather than http links for JEPs.
 - Merge branch 'master' into JDK-8285688
 - Fix title of JSR 201.
 - JDK-8285688: Add links to JEPs and JSRs to SourceVersion

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/8413/files
  - new: https://git.openjdk.java.net/jdk/pull/8413/files/39c1b70e..ff2f58fd

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=8413&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=8413&range=01-02

  Stats: 6625 lines in 156 files changed: 5437 ins; 493 del; 695 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8413.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8413/head:pull/8413

PR: https://git.openjdk.java.net/jdk/pull/8413