API edits to avoid implying that JSON-LD is not RDF

As promised, attached are suggested edits to the "JSON-LD 1.0 Processing
Algorithms and API" document at

  http://json-ld.org/spec/latest/json-ld-api/index.html

The purpose of these edits is to avoid implying that JSON-LD is not RDF.

The main strategy was to change phrases like "transforms JSON-LD to
RDF" and "converts RDF to JSON-LD" to phrases like "deserializes JSON-LD
to RDF" and "serializes RDF to JSON-LD".

Note that some of the section titles changed as a result, and two HTML
anchors were also changed:

  convert-to-rdf-algorithm --> deserialize-to-rdf-algorithm

  convert-from-rdf-algorithm --> serialize-from-rdf-algorithm

Therefore other documents that reference this document may need to
be updated correspondingly.
Fix markup

No other changes
Syntax doc edits to avoid implying that JSON-LD is not RDF

Attached are the corresponding changes that I see that are needed in the
syntax document: http://json-ld.org/spec/latest/json-ld/

Other editorial issues that I noticed but I did not fix in the attached
version:

1. The Abstract begins: "JSON is a useful data serialization and
messaging format".  Delete "useful" or perhaps delete the whole
sentence.  (Other data serialization and messaging formats are *not*
useful?)

2. The Features at Risk section needs to be updated regarding blank
nodes as predicates.
Minor tweaks to make it clearer what the algorithms are supposed to do
Minor tweaks

Taking into consideration the discussion in https://github.com/json-ld/json-ld.org/pull/287.
Fix typo
Clarify that a generalized RDF Dataset is a non-standard extension of RDF
Update index.html

tiny grammar fix
Merge pull request #289 from bollwyvl/patch-1

Update index.html
Merge pull request #287 from lanthaler/dbooth-api-spec-changes

David Booth's API edits to avoid implying that JSON-LD is not RDF
Merge pull request #288 from lanthaler/dbooth-syntax-spec-changes

Syntax doc edits to avoid implying that JSON-LD is not RDF
Update test manifest names and descriptions

in response to a discussion with pkuyken on IRC. Section titles such as "JSON-LD to Expansion tests use object compare" are not very useful (and actually the same title was used twice).

@gkellogg: Could you please update the report generator template to use the names as section title (instead of the description) and to also include the description. Thanks
Update earl reports with latest version of gem and updated template.
This addresses the issue noted in commit 5abcf946faef5578a4cc4e4931470d8c3454e4f8
Update Ruby JSON-LD EARL report.
Fix test file locations.
Added data model intro section, fixed flow of doc for beginner readers.
Minor word change to aid understanding in data model section.
Basic Schema.org context
New line added to the eof
Fixed minor grammatical issue in JSON-LD Syntax spec.