fix rechit embedding for electrons to ensure all needed crystals are included (5x5 around every subcluster seed xtal plus all xtals in supercluster)
really fix electron rechit embedding
extend cluster and rechit embedding to photons
add read-time relinking of CaloCluster references in embedded SuperClusters
Merged micro-from700 from repository bendavid
add packed gen class
Merge branch 'test-josh' into micro-from700-andrea