added finest histogram for error computation
added finest histogram for error computation

eaulisa/MyFEMuS,giorgiobornia/femus,saikanth88/femus,FeMTTU/femus,FeMTTU/femus,giorgiobornia/femus,giorgiobornia/femus,saikanth88/femus,eaulisa/MyFEMuS,eaulisa/MyFEMuS,saikanth88/femus,FeMTTU/femus,FeMTTU/femus,saikanth88/femus,giorgiobornia/femus