Simplify check in JsonLD::parse() to distinguish between JSON input and filename
Do not overwrite @type when converting to RDF
Ignore all keywords apart from @id, @type, and @list when converting nodes to RDF
Rely on newline character at the end of a toRdf test

as other's do. See https://github.com/json-ld/json-ld.org/commit/177b5041c9fc145d84ddb307b8f11c86c805fca2#commitcomment-3365483
Allow empty array as default value when framing
Merge branch 'master' into expansion-debug

[ci skip] since the tests are currently broken