CHANGES FROM 6.1 TO 6.2

calculation of potential evaporation (using stomatal conductance without soil moisture limitation)

development of groundwater simulation
	recharging of soil moisture in groundwater (net loss for the system)
	if groundwater table is in actual layer (above lower boundary): GWlayer = actual layer, lower layers are charged
	soil layers below the groundwater table are saturated - net water gain from soil system
	new output variables for recharging fluxes and pools: GW_recharge (227-236), groundwater_snk (129)
	thickness of capillary zone is calculated by the model based on soil type (and literautre data) and it is regulated based ont eh ratio of actual potential evaporation and theroetically maximum of potential evaporation
	two methods for GW-calculations
		method1: GW affects soil moisture conditions if distance(between capillary zone and midpoint of the layer) is less than a critical value - increasing of VWCfc, water from GW (net gain)
		method2: GW affects soil moisture conditions if distance(between capillary zone and depth of the layer) is less than a critical value - increasing of water from GW (net gain) depending on the position of capillary zone

bug fixation in cutdown_to_litter.c (litter fluxes of belowground cut-down material)

bug fixation in dayphen.c (incorrect value assignment of the variable offday)

development of optional input reading: using year information in onday/offday/mortality/conductance/groundwater

bug fixation in fertilizing_init.c: free fertilizing date variables

development of actual evaporation calculation - effect of groundwater

development of thinning: thinning affects also the root biomass of the trees (to the same extent as the aboeground biomass)
	new output variables: root biomass to THN (carbon: 1187-1198, nitrogen: 2061-2072)

development of tipping.c: 
	tipping diffusion limitation
	in case of saturation - also  percolation

development of Richards: finer spatial resolution
	calculation of actual value of hydrological diffusivity and conductivity

small but high impact bug fixation in daily_allocation.c - c allocation calculation is corrected in N-limited situations