Support for Dashes and Meta/Tax Queries

This commit adds support for post types and taxonomy terms that have dashes in their name (e.g. taxonomy called annual-meeting). Additionally it adds support for meta_query and tax_query as per http://codex.wordpress.org/Class_Reference/WP_Query#Taxonomy_Parameters / http://codex.wordpress.org/Class_Reference/WP_Query#Custom_Field_Parameters.

For dashes the regex was updated from \w+ to [\w\-]+

Example of a tax_query in Ember.js:

```js
APP.SessionsTypeRoute = Ember.Route.extend({
	model: function(params) {
		var tax_query = new Array({"taxonomy":"session-type", "field":"slug", "terms":params.slug}),
			  ses = this.store.find('post', {'type' : 'session', 'filter[tax_query]' : tax_query});
		return ses;
	}
});
```