Revert "Revert "Reaching code coverage Nirvana through Runkit and shenanigans""

This reverts commit e88928dd5bf5adb0021064892acc1929c7f9934f.
Revert "Disabled Runkit for the time being, see if it fixes Travis crashes"

This reverts commit 8244a97317cd7f890e79ce32d6790b0a9d844a25.
WiP