libsedml.so should depend on libnuml.so, libsedml-static.a should be built without -fPIC

[yurivict]

Linking libnuml.a into libsedml.so is wrong, see NuML/NuML#22

While building libsedml-static.a --fPICshouldn't be used.

[fbergmann]

we need to find a solution that involves all the libraries and does not break things for people. So i so solving this first for numl / libsbml in NuML/NuML#22 would make most sense to me.