Updated for version 1.0.1

This is the first official release of the ugrid_functions module. 
This module adds a server side function to Hyrax that allows a 
user to request domain subsets of unstructured gridded data sets 
that conform to the convention described here: 

    https://github.com/ugrid-conventions/ugrid-conventions

The subsetting function is called "ugr5". The syntax/usage statement
for the function is returned when the function is invoked without
parameters:

    http://<server>/opendap/<datsetname>.ascii?ugr5()
    
NOTE While modules that read data (like netCDF or HDF5) are listed 
in the Hyrax server's 'version' response, the ugrid_functions module
will not be listed there. Use the above URL to test to see if the
handler has been loaded by the server.
    
This initial version is only compatibly with irregular triangular 
meshes. Both the Ugrid convention (see above link) and the gridfields 
library which implements the heavy lifting support other types of
unstructured grids so in the future support for these may be added.

NOTE: Installing the BES from RPM packages and using this handler?

As of 9 May 2014, the ugrid functions handler does not have a RPM
package (because libgridfields does not) and so must be built from
source. It's very easy to combine a Hyrax install from the RPMs with
one or more handlers built from source, but it does require a little
bit of information about how the BES configuration files work. Lets
assume the following scenario: The BES has been installed using RPMs,
meaning that both the framework and a small number of handlers are 
in /usr/lib/bes or /usr/lib64/bes and their corresponding configuration
files are in /etc/bes and /etc/bes/modules. When the ugrid functions
handler is built from source using './configure --with-gridfields=...'
the resulting module and conf file will be installed in /usr/local/lib{64}
and /usr/local/etc/bes/modules (that's the default for anything built
using 'configure'). You need to tell the BES server to load that 
module and the way to do that without copying files, etc., is to add
the following to /etc/bes/bes.conf:

BES.Include=/usr/local/etc/bes/modules/.*\.conf$

That line will instruct the BES to load all of the module configuration 
files in /usr/local/etc/bes/modules/. I think this is the easiest way.

Is there another way? Yes, there are two other ways to combine a BES 
installed using RPMs with one or more handlers built from source. The
first way is to run configure with the following switches:

--prefix=/usr --sysconfdir=/etc <other switches>

Which will install the newly built code in the correct places. The second
way is to build and install the software and then copy the libugrid_function.so
and ugrid_functions.conf files to /usr/lib{64}/bes and /etc/bes/modules 
(respectively) and then edit the ugrid_functions.conf file so that the 
module pathname is correct.

The easiest way to combine a RPM installation of Hyrax with other modules 
built from source is to build the other modules using the default prefix 
supplied by configure and then edit the bes.conf file that the RPMs installed
in /etc/bes/. Running configure with the the '--sysconfdir' and other switches
is probably next in line and copying/editing the files is likely to be 
the most work.