Fix a logical error in two if-clauses
Add optional properties to RDFauthor

Add the possiblity to add optional properties to the popover mode of
RDFauthor. These properties will be added to a 'template' section in the
'Add Property' dialog.
Modify help menu building process

Do not add links for empty URLs.
Deactivate ckan, mail and pingback extension

ckan, mail and pingback are deactivated by default now
Disable (most) reloads for RDFauthor
Forward Erfurt submodule
Adapt dist vagrant file to us hashicorp precise64 base machine, add vbox name
Add support for attributes in toolbar buttons
Fix minor cs issues
User HTTP_HOST instead of SERVER_NAME

SERVER_NAME holds the name configured in the server setting and thus can
not be used, if the same server is used under different names.
HTTP_HOST instead contains the currently requested hostname. This also
includes the correct format for IPv6 in URLs and a port if appended.
Default HTTP_HOST to localhost if not set
Forward Erfurt and RDFauthor
Merge branch 'develop' into deployment/erm-hd

Conflicts:
	libraries/Erfurt
Merge branch 'feature/rdfauthor-FormBuilder' into deployment/erm-hd

Conflicts:
	extensions/themes/silverblue/scripts/support.js
forward submodule 'Erfurt'
forward submodule 'template'
forward submodule 'RDFauthor'
'Classes' is default again