Merge pull request #256 from stain/hd-logos

High resolution PNGs of logos (width=1920)

This closes #256
Ensure that toRdf tests end with a new-line character

See https://github.com/json-ld/json-ld.org/commit/177b5041c9fc145d84ddb307b8f11c86c805fca2#commitcomment-3365483
Remove extra end of lines for empty output (no quads).
Change renamed bnode ordering.
When @base is null, it sets base to null (makes IRIs relative).
bnodes relabeled by nodeMapGeneration are not relabeled again by toRDF

See discussion starting at https://github.com/json-ld/json-ld.org/commit/177b5041c9fc145d84ddb307b8f11c86c805fca2#commitcomment-3373786
Ensure determinism of the Convert to RDF Algorithm by specifying the processing order

See discussion at https://github.com/json-ld/json-ld.org/commit/177b5041c9fc145d84ddb307b8f11c86c805fca2#commitcomment-3373786
Change the default value of "use native types" flag to false

This addresses RDF-ISSUE-129. See http://www.w3.org/2011/rdf-wg/track/issues/129

@msporny @niklasl @gkellogg @dlongley @sandhawk What should we do with the tests now? Should we duplicate (the ones affected by this change) and specify the value of the flag in the test?
Remove feature at risk marker for reverse properties

This addresses RDF-ISSUE-133. See http://www.w3.org/2011/rdf-wg/track/issues/133
Fix copy-paste error
Link "RDF Dataset" to RDF Concepts as requested by David Booth

See http://lists.w3.org/Archives/Public/public-rdf-comments/2013Jun/0029.html
Adopt change 5.S1 proposed by the GLD WG in #254
Adopt change 5.S2 proposed by the GLD WG in #254
Adopt change 0.S1 proposed by the GLD WG in #254
Adopt change 1.S2 proposed by the GLD WG in #254

and remove the part "in the case of JSON-LD this is the base location of the document" since we now also have @base.
Adopt change 8.3S1 proposed by the GLD WG in #254
Adopt change 8.3.S2 proposed by the GLD WG in #254
Adopt change 8.5.S1 proposed by the GLD WG in #254
Adopt change 9.2.S1 proposed by the GLD WG in #254
Adopt change 9.2.S2 proposed by the GLD WG in #254