…M#2557

We build `osrm_contract` (the library) linking in libtbb. We then
build `osrm-contract` (the binary) linking in `osrm_contract` (the
library).

Because we're only using TBB's `parallel_invoke` in the code for the
binary, it seems like the linker discards some symbols in the library.

Therefore we have to link libtbb for the binary again. Even worse, the
order now matters: if we first link in `osrm_contract` and then libtbb,
we're still hitting the issue re. discarded symbols.

Therefore we first link in all dependencies (libtbb, libboost*), and
only then `osrm_contract`.

Strictly speaking, we probably have to do this for all of our binary
targets, or we will hit similar issues in the future.