RFR: Updated section on Code Conventions. [v2]

[Andreas Lundblad]

> Pull request for adding code conventions.
> 
> The code conventions in this pull request is a verbatim copy of [3]. These conventions were the ones discussed in
> detail on discuss at openjdk.java.net in 2015. Two rounds of reviews were performed, [1] [2], and all comments were
> addressed. The 6th and last draft [3] has been stable since then, and been in use by several OpenJDK projects.  [1]
> http://mail.openjdk.java.net/pipermail/discuss/2015-August/003766.html [2]
> http://mail.openjdk.java.net/pipermail/discuss/2015-August/003771.html [3]
> http://cr.openjdk.java.net/~alundblad/styleguide/index-v6.html

Andreas Lundblad has updated the pull request incrementally with three additional commits since the last revision:

 - Moved Javadoc guidelines to comments section.
 - Joined code blocks into a single one in hgHelp and tClone.
 - Changed from ``` to ~~~, and from 'document' to 'section'

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

Changes:
  - all: https://git.openjdk.java.net/guide/pull/14/files
  - new: https://git.openjdk.java.net/guide/pull/14/files/2ca5accd..65db3f10

Webrevs:
 - full: https://webrevs.openjdk.java.net/guide/14/webrev.01
 - incr: https://webrevs.openjdk.java.net/guide/14/webrev.00-01

  Stats: 480 lines in 4 files changed: 195 ins; 49 del; 236 mod
  Patch: https://git.openjdk.java.net/guide/pull/14.diff
  Fetch: git fetch https://git.openjdk.java.net/guide pull/14/head:pull/14

PR: https://git.openjdk.java.net/guide/pull/14