Add configuration of Cross-Origin Resource Sharing.

Hook up Spring so that the CORS filter can access configuration
information in threddsConfig.xml. This allows controlling CORS from
our standard configuration files.
COverity fix; unused variable
Merge pull request #83 from dopplershift/cors

Add configuration of Cross-Origin Resource Sharing.
A few more NetCDF-4 C library loading tweaks.
Merge branch '4.5.4' of https://github.com/Unidata/thredds into 4.5.4
Made NCSS output file naming more consistent and robust.
* Fixed GridAsPoint writer bug when Z axis has no "positive" attribute.