Implementing Ivan Ristic microphysics and convection scheme in v4.5.1

[Nikolar97]

In order to correctly implement IR microphysics and convection scheme fallowing
changes are important to make in namelist.input:

1. To include IR microphysics scheme in the namelist.input:

	mp_physics                    = 150,
	icloud                        = 4,

    (during the process of verifing the scheme and in order for
    scheme to be accepted, Jimy Dudhia from the WRF team suggested a new value 
for icloud and proposed number 4. New value for icloud is needed in 
order to use IR microphysics cloud cover in the radiation scheme and output)

2. To include IR convection scheme in the namelist.input set up:

	cu_physics                    = 147,


3. Very important step for setting up when to call radiation scheme (GDFL, Dudhia scheme, RRTMG...) :

	ra_call_offset                = -1,

this option allows us to call radiation scheme one timestep before output 
    and to update cloud cover with latest value from IR microphysics.

   4. For radiation scheme we suggest to use GFDL scheme and setup:

	ra_lw_physics                 = 99,
	ra_sw_physics                 = 99,

any other option for radiation scheme is allowed but this scheme creates better look of 
convective clouds on the map (using any other scheme will only include 
stratiform clouds)