[TYPO3-ect] Announcing TER cleanup process

[Georg Ringer]

Hi,

if there is a security issue, all extension versions are locked,
including the previous ones but:

Imagine those versions of an extension:
1.1.0
1.1.1
1.1.3
2.0.0
2.0.1
2.0.2

if an extension author wants to maintian the 1.x.x branch too, he can of
course still do so by changing the version of the extension to 1.1.3 and
upload it again and it will be shown as (depending what the author
choose) as 1.2.0 or 1.1.4.

this still works if e.g. 1.1.3 has been removed because of a security issue

Georg