Bug fixes in warm rain diagnostics (MODIS/CloudSat joint products) (#47)

* Bug fixes in warm rain diagnostics

Closes #39, #41. Known-good output is updated. 

In cosp.F90, variables for warm rain diagnostics are always allocated
even when the diagnostics are switched off. I have modified the
allocation issue (issue #39).

Also I have changed the dimension size of "frac_out" which through in
the warm rain diagnostics in the case of "use_vgrid=.true.".
The variable "frac_out" is interpolated in vertical so that the
vertical levels of frac_out and CloudSat radar reflectivity are
now consistent each other (issue #41).