[Backport] GEOS-5332 KMLTransformer does not include sld and vendor para...

...meters into the request
Improve reflector arguments recognition
Add JUnit tests
Comment out deprecated methods form GetMapRequest
Fix problem introduced by previous commit
GEOS-5332 Fix the patch as requested
fixed as requested
remove formatting
remove comments

NOTE: this is the backport for:
https://github.com/geoserver/geoserver/pull/73

It is essentially the same with some minor changes to the KVPUtils due to recent changes into the master branch.
Cheers,
Carlo