Add sublime files to gitignore and add new embed test.
Add aggressive embed support.

See: http://json-ld.org/spec/latest/json-ld-framing/#framing-algorithm

Removed 4.4.4 logic and added checks for circular reference injection
prior to the recursive calls at 6.2.3.1.1 and 6.2.3.2.
Support local tests by loading relative URLs locally.

- When bailing, display exception if it is not an assertion
  error (assertion errors have custom output logged already).
Add embed support for "@once", "@never", and "@always".

- "@once" matches the old "embed: true" behavior; a maximum
  of one embed will added -- and preference will be given to
  an explicit request for an embed. This is the default because
  it does not add triples.
- "@never" matches the old "embed: false" behavior; no embeds
  will occur.
- "@always" is a new feature; it is "aggressive re-embedding"
  meaning that an embed will always occur unless it will cause
  a circular reference.
- Keep backwards-compatible support for embed: true/false; where
  true => "@once" and false => "@never".
Don't run WebIDL when non-standard JSON-LD test suite path is used.
Use new @embed syntax.
Add local test directives and run them by default.