updated ContentTypeInterceptor to check accept header, various refactoring of other interceptors, added testcase
Merge branch 'master' of github.com:callista-software/dynamic-routing-gateway

Conflicts:
	drg-webcomp/src/main/java/se/callistasoftware/drg/web/WebEndpointConfigurationUtil.java
	drg-webcomp/src/main/java/se/callistasoftware/drg/web/interceptors/DrgContentTypeInterceptor.java