Adding page URL to previewer page data.
Adding social bar widget.
Require 'forwardable' in sprockets (bugfix)
Actually search the rest of the document

Do what the comment says. The offset parameter to with_index simply sets
the index offset, not the iteration offset.

Also closes #154.
Merge pull request #167 from Stebalien/fix-sprockets-forwardable

Require 'forwardable' in sprockets plugin.
Merge pull request #168 from Stebalien/fix-summary-generation

with_index does not set the iteration offset.
Reorganize/fix the Sprockets Plugin

The compile function of the sprockets plugin was out of sync with the
rest of ruhoh and no longer worked. In the process of fixing it, I ended
up reogranizing the previewer and compiler code to match the layout of
Ruhoh's built-in compiler code as much as possible.
Merge pull request #169 from Stebalien/reorganize-sprockets-plugin

Reorganize/fix the Sprockets Plugin
Merge pull request #163 from lynnfaraday/2.1_paginator_preview_url

Adding page URL to previewer page data.
Render widgets within the full master page context.

Should fix #160 and fix #164.
Merge with latest widget context changes from upstream.