Finish 1.1.2.1.
A revision to pulled 1.1.2, which allows URI subjects and deals more sanely with initializers.

If a `values` initializer is set with an empty list, `subject` will be used as the first element in the list. Otherwise, if the list is not empty, `subject` identifies the first element of the list to which `values` are prepended yielding a new `subject`. Otherwise, if there are no initial `values`, and `subject` does not identify an existing list in `graph`, `subject` is left as is, but the list will be invalid.
Update schema.org vocabulary definitions to match 1.0f release.
These are comment only changes, so they don't change the behavior of the gem at all.
add gem:build/release rake targets.
Change .gemspec to rdf.gemspec for Windows compatibility.
add gem:build/release rake targets.
Add the MO vocab
Merge pull request #149 from samphippen/add-mo

Add the MO vocab. Thanks, good idea.
Change terminology from "plugin" to "extension"
Change terminology from "plugin" to "extension"
Fix readme spec in JRuby
Update schema.org vocabulary definitions.
Rename use of _plugin_ to _extension_.
Added Ruby 2.1.1 to Travis
Merge branch 'develop' of github.com:ruby-rdf/rdf into develop
Add RDF::List#to_rdf as an alias for RDF::List#each_statement. This allows the pattern of creating an anonymous list and appending it to an existing Writable (such as a Graph or Repository).

This addresses issue #150.
Version 1.1.3.
Update dependencies and gem build/release tasks.
Finish 1.1.3