v. 2.10, PS 25/08/2010

- Changed usage of EnKF. Now the parameters are communicated to the program via
  a file with Fortran name list, passed as the first parameter.

- Added a new module m_parameters.F90 to handle the above.

- Pass the inflation magnitude as a parameter to update_fields(), rather than 
  calc_X5(). This enables to vary inflation depending on the updated field, 
  which is necessary for parameter estimation

- Created a new modue m_uobs.F90 and moved there get_uobs(), now renamed as 
  uobs_get().

- Added pieces of code to handle estimation for SST and SSH biases. The 
  corresponding 2D fields are supposed to be named as "sstb" and "msshb". The
  estimates are subtracted from the ensemble fields of those in prep_4_EnKF().
  Also, the estimate for SST  bias is subtracted from the in-situ T fields in
  the ixed layer, smoothed by a factor exp(-(z /mld)**2).

- Removed m_read_mean_ssh.F90. There is a duplication of this procedure placed
  now in p_prep_4_EnKF.F90 in Prep/m_get_def_wet_point.F90, which is to removed
  in future.

- Made "obs" and "nobs" global throughout the code, residing in m_obs. 
  Accordingly, the variable name for local observations in m_local_analysis.F90
  became "lobs" and "nlobs". 

- Made all observation tags in capital letters (backward compatible).

- removed m_datatest.F90; moved testing the obs range to m_obs.F90.
