oq-platform: Improve visualization of geodetic strain rate

[Matteo Nastasi]

GOAL: run geonode 1.2 with GeoServer 2.2 to be able to use new raster-to-vector GS tools.

DONE - Package a custom version of geonode 1.2 with GS 2.2 (repo: opengeo/geoserver-2.2-configurable)
DONE - Avoid security integration issue relaxing postgresql security (we will return on it if all other steps seems good enough)
DONE - Importing GeoServer data from 2.1 to 2.2
DONE - Install GS extensions to enable raster-to-vector filters
DONE - Use filters to render geodetic (work in the layer-preview but not into application, needs more investigation)
TODO - Perform performance and quality tests
TODO - Fix security issue (not mandatory for the goal)

The experiment was performed but currently we decide to not add to our code.