Windows compatibilty patches (rebased to develop)

copy of https://github.com/DennisOSRM/Project-OSRM/pull/979
with `develop` as  base branch.

Or we can just use INT_MAX  and UINT_MAX:
```constexpr unsigned stxxl_memory = ((sizeof(std::size_t) == 4) ? UINT_MAX: UINT_MAX;```
should compile.