TYPO3 Core

By using relative submodule URLs, we can make use of Gerrit's submodule subscription feature.

This automatically updates the Core repository, if a change is merged in a submodule (e.g. extbase).

For end users, these are the consequences:

• It is easier, to have a TYPO3 mirror on an own server, as the submodules also point to the same server, instead of to typo3.org
• Users, which have the git port blocked, can clone the Core through ssh/https and submodules will be automatically transferred through the same protocol
• No change is required for users with a checkout. If they issue a git submodule sync, their .git/config will be updated (and the url for the submodules will be calculated based on the URL of the default remote + the relative URLs of the submodules.