[TYPO3-doc] Updating version in documentation

[Georg Grossberger]

I added this hook in the latest release, which also fixes some other 
"suggestions" I received on twitter.

To be completely honest on this issue: this should not be automated at all!

A documentation author should state manually / explicitly for which 
version of the software the docs have been written. If the version is 
outdated, this shows the user, that no interfaces (in the code, the cli, 
the GUI et. al) have been added or altered.

If I write about some new features in a 2.1 release, I don't want the 
docs to state 2.1.3 if I fix a bug. Instead I should manually update the 
docs, if a behaviour is changed.

In this sense, I think it's sufficient to state the minor version of 
your extension in the docs (like, 2.1, 1.5, ...) as long as you keep to 
TYPO3s semver versioning.

This also offers the possibility to show docs for several versions, but 
only if they change, because a feature needed to be changed. To have the 
exact same documentation four times because you just update some inline 
comments, fix a security issue or add some testcases, does not make much 
sense.


> I send a feature request for a hook in the new extension_uploader:
>
> https://github.com/Trenker/typo3.extension_uploader/issues/3
>
> Regards
>
> Elmar