Changed logging levels for messages in DiskStorage
Making sure queue exists
Refactored IndexLinkFinder
Refactored JsonLDLinkCompleterFilter
Merge branch 'master' of github.com:libris/librisxl

Conflicts:
	whelk-core/src/main/groovy/components/DiskStorage.groovy
	whelk-core/src/main/groovy/whelks/StandardWhelk.groovy