the ParticleConfiguration class now exposes its internal objects via getter methods that return constant references (this is in line with the recent change to the Wmatrix and TVector classes)
added a particle configuration observable that records the configuration once every bin (it can be used to see if the correlations are uncorrelated and will be employed to reuse an old configuration as the starting configuration for the next iteration in the SR cycle)
some preparations for the upcoming performance optimization of the model initialization
subsequent SR iterations will now use previously generated particle configurations as their initial configuration and shorten the equilibration period by a factor of 10
merged initialization optimizations from master