Changed bloql interface to avoid polluting `this.props` object and make it easier to access for posts

• Changed bloql interface to avoid polluting this.props object and make it easier to access for posts:

  for PostList:

  {this.props.posts.edges.map(edge =>
  <a href={edge.node.meta.slug}>{edge.node.meta.title}</a>
  )}
  // becomes:
  {this.props.bloql.posts.map(post =>
  <a href={post.meta.slug}>{post.meta.title}</a>
  )}

  for Post (to avoid polluting this.props, in case a user wants to have pass his own post prop, we shouldn't override it):

  this.props.post
  // becomes:
  this.props.bloql.post