Adding Cobertura to get test coverage reports

Generate the reports this way:
$ mvn cobertura:cobertura

This would generate the report into:
${project.dir}/target/site/cobertura/
Adding utests on ExpiredArchiveDaemon

- new utests
- Fixing bugs in expired archive removal
Removing unused file
Adding utests on ExtractorController
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.
Organizing imports on ExpiredArchiveDaemonTest
Fixing typo in TaskDescriptor
Adding tests on updateTask (wip)
Adding tests on BoundWcsRequest + ExtractorController

This is still in a WIP state ;
TODO: how to resolve test resources files (getResource does not seem to
work)
TODO: Finishing the mock of the HttpResponse
Improving code coverage on BoundWcsRequest

Adding getcapabilities / descripbecoverage samples (from
http://sdi.georchestra.org).

Coverage should be OK for this class, moving forward.
Update BoundWcsRequest testsuite

Better handling of test resources, removing extra System.out.println.
Add test for ExtractorLayerRequest class
add wfs extractorapp test
Merge branch 'AddExtractorappTests' into extractorapp-improving-automated-testsuite

Conflicts:
	config/defaults/security-proxy/maven.filter
	extractorapp/pom.xml
Test KML extraction.
Fixed test failure on windows.

enable tests on security-proxy and extractorap
Add WcsReaderRequest tests
Added test for CSWExtractor.

Factored out a super class for all tests that need a server
Adding utests on GDALCommandLine

TODO: not sure on what to test actually, it might be improved, need to
see with @jeichar.
Adding tests for ScaleUtils