Changed FileNotFOundException to 'return null'

Changed processing of 'file not found' to be same as 'no file specified'
Merge pull request #236 from marks60/my_bugfix

Changed FileNotFOundException to 'return null'
[GEOS-5810] Packaging error for the CAS extension
Update to latest GeoScript JS to work with GeoTools 9, forward port of #237
Use stricter file patterns for CSS packaging
GEOS-5809 Support namespaces in WFS 2.0 fes filters
GEOS-5796 X-Paths with predicates only work with @attribute references
GEOS-5825,Missing jar for Jpg2K and GDAL Extension
Merge pull request #241 from geosolutions-it/master-fix

GEOS-5825,Missing jar for Jpg2K and GDAL Extension
Make sure the test is running in a clean enviroment (no stale manifest.properties in the root of the main module)
[GEOS-5754] Some 'Save' buttons do not work with Google Chrome
[GEOS-5754] Some 'Save' buttons do not work with Google Chrome, improved patch
Superoverlay code re-integrated, network link generation code cleaned up, still needs more testing
GEOS-5826 allow request parameters access from HTMLFeatureInfoOutputFormat content templates
Fix GEOS-5796 test
[GEOS-5370] WPS requests fail when performed on a secured layer
[GEOS-5536] GeoWebCache settings won't be persisted on Windows
Merge pull request #243 from aaime/geos-5730

[GEOS-5370] WPS requests fail when performed on a secured layer
[GEOS-5836] Editing some GUI elements can result in config changes even without saving
GEOS-5826 simplified patch and removed regression