[mod] use double quotes for values of html attributes, to keep it more standardized
Merge branch 'develop' of https://github.com/AKSW/site.ontowiki into develop
[mod] use double quotes for values of html attributes, to keep it more standardized
[mod] add lang parameter additionally to xml:lang to keep code valide
Static values in literal helper

When only markup is needed.
Use static
Allow array values for rel and rev
Fix empty rel and rev
Handle img, link and other empty elements
Allow to specify a type for static value
Comments
Use <meta/> instead of <data/>
Microdata tweaks
Format date
Generate titles for URIs in literal helper
Don't generate excess empty elements
Merge branch 'develop' into feature/schemaSite