Move dictionaries to i18n

@eclarizio I agree, I don't like the parens, but it doesn't work without them.  I tried out the "DRY" approach but I think it becomes too wordy.  I wanted to avoid scrolling because I think the context starts to get lost.

```ruby
  context ".gettext" do
    subject { described_class.gettext(lookup, options) }

    context "with text only" do
      context "and not found" do
        let(:lookup) { "abc" }
        it { should eq("abc") }
      end

      context "as a column entry" do
        let(:lookup) { "active" }
        it { should eq("Active") }
      end
      ...
    end
  end
```

vs

```ruby
  context ".gettext" do
    context "with text only" do
      it("and not found")     { expect(described_class.gettext("abc")).to    eq("abc") }
      it("as a column entry") { expect(described_class.gettext("active")).to eq("Active") }
      ...
    end
  end
```