I am modifying wpapi-vagrant-varietal, the VM environment against
which these integration tests are run, to include some custom
post types and taxonomies. This change will prevent that commit
from breaking these integration tests because it switches to
validating that what we expect to be there is there, not that it
is the only content available.

This eliminates all of the tests using the legacy approach of validating
the integration between our library and superagent, instead of testing the
actual public service of the library's methods

- Meta endpoint has been superseded by register_meta functionality
- Auth has moved into the HTTP Transport object
- Pages do not have comment support

Also (and unrelatedly, mea culpa) removes the functionality of `.context()`
which would set authentication when called with "edit"; it is not the
responsibility of the client to enforce authentication, that's the API's job

registerRoute now takes an optional `param` array on its configuration
object; this array can contain strings that will trigger existing mixins
(like `filter` to be applied to the generated handler:)

```js
site.handler = site.registerRoute( 'myplugin/v1', 'collection/(?P<id>)', {
    // Listing any of these parameters will assign the built-in
    // chaining method that handles the parameter:
    params: [ 'filter', 'before', 'after', 'author', 'parent', 'post' ]
});
// yields
site.handler().forPost( 8 ).author( 92 ).filter( 'etc', 'etera' )...
```

but if the `params` array contains a parameter name string that does not
map to an existing parameter setter, a basic setter for that parameter
will be auto-generated:

```js
site.books = site.registerRoute( 'myplugin/v1', 'books/(?P<id>)', {
    params: [ 'genre' ]
});
// yields "myplugin/v1/books?genre[]=19&genre[]=2000"
site.books().genre([ 19, 2000 ]).toString()
```

Full changes:

- Add support for all the most common first-party query parameters
  (where commonality is a function of number of routes on which the
  parameter can be used successfully):
  + `_embed`, `context`, `exclude`, `include`, `offset`, `order`,
  `orderby`, `page`, `perPage`, `search`, and `slug` are supported
  wherever WPRequests are sold (closes #178)
- Add ability to apply existing mixins to `registerRoute`-registered
  handler methods by referencing the parameter name (fixes #203)
- Add ability to auto-generate a basic `.param()` convenience wrapper
  for any given query parameter when using `registerRoute`
- Document `.param` method & its derivatives (fixes #226)
- Pork-Barrel the addition of a 404 page to the docs site
- Remove skipped test blocks for deprecated methods
- Clean up and standardize several test files
- Resolve some general docs issues