RFR: JDK-8280738: Minor cleanup for HtmlStyle [v2]

[Jonathan Gibbons]

> Please review a simple update to reorder some members of the enum `HtmlStyle`, and to make some minor updates to the comments.
> 
> This is to facilitate automated extraction of information into an upcoming new spec for the output from the standard doclet.

Jonathan Gibbons has updated the pull request incrementally with one additional commit since the last revision:

  fix missing paren

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/7235/files
  - new: https://git.openjdk.java.net/jdk/pull/7235/files/df8c810e..0f8d94c5

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=7235&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=7235&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7235.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7235/head:pull/7235

PR: https://git.openjdk.java.net/jdk/pull/7235