1st time ja-JP translation commit.
some translations corrected.
Merge branch 'master' into ja-JP
add ja-JP directory
GettingStarted.tid plugin.info
some translation added
signed in CLA
Update test for previous commit

Test should have been updated with
dad60cda05c29974e5ae74aa488fa5c31a177504
Merge pull request #558 from pekopeko1/japanese

Translation to Japanese.
Include Japanese translation in tiddlywiki.com

All of which is making index.html far too big, which we’ll address with
a plugin library.
Release note updates
Docs updates
Update command line helps Japanese Translation.
Update some translations.
Get rid of the home button

I’m not keen on it because it ends up being very visually prominent for
something that’s not particularly useful.
Update release date for 5.0.9
Version number update for 5.0.9-beta
Docs fixes
Docs fixes
add a backup info for the Upgrade tiddler.