Distributor and Collector objects moved to Storage

Restructured code so the (Atom|Group)(Distributor|Collector) objects are
now members of the (Atom|Group)Storage classes instead of the configIo
class.  This required doing the associating/initializing/allocating of
these objects only once inside the simulation class.  As a result of
this, specifying the parameters (atom|bond|angle|dihedral)CacheCapacity
inside the parameter file will no longer do anything.  These parameters
have all been hardcoded to 100.
Similarly, please call the member objects simply "distributor_" and "collector_". The "Atom" part is clear from context.  You should be able to make this change with a simple text substitution within this class, since the member variables are private.