add logo files
minor formatting
add credits
adjust colorBrand color
adjust colorNotice
Merge branch 'master' of github.com:denkmal/denkmal.org into issue-78

Conflicts:
	library/Denkmal/layout/default/variables.less
add responsiveness to credits section
show retina-ready map image
add background pattern
EventList / EventAdd styles
Merge pull request #78 from christopheschwyzer/issue-78

add credits