Add support for selectordinal statements

Makes this work:
```
The {FLOOR, selectordinal, =0{ground} one{#st} two{#nd} few{#rd} other{#th}} floor.
```

As discussed at eemeli/make-plural.js#1, this depends on make-plural.js 2.0.0. Also includes a bunch of new tests for the new functionality, and updates to the examples

Not included are any updates to the readme, which really ought to happen if this gets included. Also, if we drop the global utility functions as discussed at jquery/globalize#321, I can rebase this change on those -- there's some overlap in changes to the runtime functions.