Added hyphen to 'Timeago' in third-party plugins list.
Adding jekyll-swfobject to plugins.md
Merge pull request #1263 from sectore/master

plugin jekyll-swfobject
Merge changes on docs/plugins/ page.
Update history to reflect merge of #1263.
Adds Jekyll Picture Tag to the Plugins page
Merge pull request #1280 from robwierzbowski/add-jpt-plugin

Adds Jekyll Picture Tag to the Plugins page
Update history to reflect merge of #1280.