[IMP-dev] Moving atom and residue types

[Daniel Russel <>]

I moved the atom and residue predfined types from being static members  
of the respective decorator (i.e IMP::core::AtomDecorator::AT_C) to  
being members of the IMP::core namespace (IMP::core::AT_C) so that  
swig could manage to export them to python. This shouldn't affect too  
much code as they were not previously usable from python, but just be  
aware.