Update 3 Dec 2013

New functions:
set_elev_tide_tmd.m
plot_fvcom_field.m
read_netcdf_vars.m

A few modifications to existing functions, mainly removing ~ as this is
incompatible with my Matlab version.
Updated some help info
A few wee edits
Merge branch 'master' of github.com:murrayr/fvcom-toolbox into rory

These changes include a few new functions and some modifications to
existing ones:

New:
    fvcom_prepro/set_elevtide_tmd.m
        * Generate tidal elevation forcing from the TMD TPXO data.
    utilities/plot_fvcom_field.m
        * Plot a given FVCOM output field.
    utilities/read_netcdf_vars.m
        * Alternative script to read FVCOM netCDF output (alternative to
        read_netCDF_FVCOM.m).

Updated:
    fvcom_prepro/get_NCEP_forcing.m
        * Added fix for data precision issues.
    fvcom_prepro/read_sms_mesh.m
        * Added fix for different header configurations.
    fvcom_prepro/write_FVCOM_forcing.m
        * Fix the triangulation array shape.
    fvcom_prepro/write_FVCOM_river.m
        * Fix the way time is converted to Modified Julian Day.
    fvcom_prepro/write_FVCOM_river_nml.m
        * Merged changes for uniform river distribution.
    utilities/read_netCDF_FVCOM.m
        * Fix Itime and Itime2 arrays.