modified particle main with more FSI stuff from Sara
modified particle main with more FSI stuff from Sara

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