Merge pull request #2 from raphaelm/master

update with latest commits from raphaelm
Added ability to show images in search results
iOPAC bug with cover images
Cover images in search results for Zones22
Bibliotheca: Fix share URL
Zones: Selector fix
added: Detmold
added: LLB Detmold
added: Garching
Merge branch 'master' of https://github.com/johan12345/opacclient into 198-covers
Introduced CoverHolder interface
Proper URL cleaning routine
SISIS: Cover in result list
Slightly enlarge cover images
Asynchronous cover loading