[IMP-dev] weight decorator

[Keren Lasker <kerenl@salilab.org>]

hi,

Currently we have a generic XYZR decorator.
For mass we have atom::Mass, but when dealing with beads, it does not  
really make sense to use it.
Do you think it makes sense to create a generic XYZRW decorator in  
core ? the default W key can be atom::Mass::get_mass_key()
??

Keren.