Could a soft dependency on multi_json abstraction be used

[abargnesi]

I see the ruby JSON implementation is used to read the input.

Would it be desired to provide a soft dependency (i.e. not declared in gemspec) on the multi_json gem? This would allow users to supply a more efficient JSON parser for their ruby engine. On MRI that is likely Oj, on JRuby that is likely jrjackson.

The required work is pretty minimal:

• Test for multi_json dependency on LOAD_PATH.
• If present, parse JSON-LD with MultiJson.load.
• If not, fall back to JSON module.

[gkellogg]

Good idea; this has been suggested before.