Revert "[TASK] EM: Add possibility to bypass system dependency checks"

The patch breaks Travis due to incomplete mocking.
Additionally was considered 'not ready' post merge. We work some more
on it.

This reverts commit 22695e3b2c5940c0be31541b16ff589390429826

Change-Id: I8194801b6be9d4c3b4f57d14d26df42df36f4b09
Reviewed-on: https://review.typo3.org/29813
Reviewed-by: Anja Leichsenring
Tested-by: Anja Leichsenring