migrate: PDF-Stuff; Fixed Enum for presentation_widget and added "PDF" to Mediabrowser
mediabrowser_filters.js.coffee => ressourcebrowser_config.js.config
Added pdf-configs
fixed spacing and syntax for "application/pdf" MIME
pdf-upload working now
Merge branch 'pdfwidget'

Conflicts:
	app/views/presentation_widget/details.html.haml