reverted marble mess

[Dirk Hohndel]

Since Tomaz hasn't had the time to fix the broken marble source (and
currently builds from source were failing) I reverted the merge of his
changes. Of course that means I need to be extra careful to handle this
branch moving forward, because if we decide to do this merge after all, I
first need to revert the revert. If this seems strange, read
https://www.kernel.org/pub/software/scm/git/docs/howto/revert-a-faulty-merge.txt
for explanation from the master's mouth (or fingers).

In the mean time, builds should work again.

And if we are lucky, Lubomir will be successful with the QtLocation
changes and we can just forget Marble.

/D