Set number of IniStates and StateEnd values when only CemaNeige is used

For initial states (e.g. RunOptions$IniStates) or final states (OutputsModel$StateEnd, we store 7 + 60(*24) + Nlayers*4 states at the daily or hourly time steps. This is not useful when only CemaNeige is used. For exemple, for GR2M we store only 2 states, not 7 + 60. I propose to modify CreateRunOptions lines accordingly:

  NState <- NULL
  if ("GR" %in% ObjectClass | "CemaNeige" %in% ObjectClass) {
    if ("hourly"  %in% ObjectClass) {
      NState <- 7 + 3 * 24 * 20+ 4 * NLayers
    }
    if ("daily"   %in% ObjectClass) {
      NState <- 7 + 3 * 20 + 4 * NLayers
    }
    if ("monthly" %in% ObjectClass) {
      NState <- 2
    }
    if ("yearly"  %in% ObjectClass) {
      NState <- 1
    }
  }

should become :

  NState <- 0
  if ("GR" %in% ObjectClass) {
    if ("hourly"  %in% ObjectClass) {
      NState <- 7 + 3 * 24 * 20
    }
    if ("daily"   %in% ObjectClass) {
      NState <- 7 + 3 * 20
    }
    if ("monthly" %in% ObjectClass) {
      NState <- 2
    }
    if ("yearly"  %in% ObjectClass) {
      NState <- 1
    }
  }  
  if ("CemaNeige" %in% ObjectClass) {
    if (!"yearly"  %in% ObjectClass) {
      NState <- NState + 4 * NLayers
    }
  }

In addition, RunModel_CemaNeige.R and CreateIniStates.R should be modified accordingly. This will ease the implementation of RunModel_CemaNeigeGR2M.