#127 Maps: improving performance with caching

[Anonymous]

Originally created by: andrius... (code.google.com)@gmail.com
Originally owned by: andrius... (code.google.com)@gmail.com

The map layers are currently quite slow to load and this could be improved by enabling caching.

The are two popular WMS tile caching solutions freely available:
geowebcache - http://geowebcache.org/
tilecache - http://tilecache.org/

A geowebcache demo of the Blue Marble layer can be found on the carbones.eu server at:
http://carbones.eu:8083/geowebcache/demo/bluemarble?gridSet=EPSG:4326&format=image/jpeg

NOTE: ncWMS has it's own built-in cache, so there would probably be no need to use an external cache for 'Cerc_Layers'. However, we experienced some memory issues when it was enabled and further testing is needed.