Miscellaneous changes

[gkellogg]

A bunch of fixes that address everything other than Framing and some toRdf tests.

• Do minimal checking to see if IRIs are valid by making sure they contain no whitespace. (804c15b93c9ff7b1c86e965a5feaa5ba0c77b3f0)
• Terms of the form of an IRI must map to the same IRI. (280a01e16bb728f4221055e102408390400f71a1)
• Terms of the form of a relative IRI may not be used as prefixes. (280a01e16bb728f4221055e102408390400f71a1)
• Keep term definitions mapping to null so they may be protected. (2613c4a26cf91d252ae7a713e666d5a90fb78ff1)
• Use localLoader for remote tests. (ff95ee28ecb99e8148c4bcbf949cf4ff7ac767f6)
• Support rel=alternate. (080e37445dfc39d16a80d4c56d86ce8ea392c32c)
  • Note XHR and Node loaders don't have their own tests.
• Always pass typeScopedContext to _expandObject. (f0d80f1ee1fc04a501ca7dca7d3e0dc502e3dd24)
• Allow a keyword to exist when expanding in _expandObject when the key is @included or @type. (f0d80f1ee1fc04a501ca7dca7d3e0dc502e3dd24)