Change security-proxy so that sec-username and sec-roles always are removed.

Added new header provider in security-proxy that checks the currently logged in user and if that user is one of the "special"/"trusted" users then it will map

imp-username -> sec-username
imp-roles -> sec-roles

Allowing trusted users to impersonate another user.  This is required for the extractorapp to enforce the security on the end user.
add wfs extractorapp test
Merge branch 'AddExtractorappTests' into extractorapp-improving-automated-testsuite

Conflicts:
	config/defaults/security-proxy/maven.filter
	extractorapp/pom.xml