add fluentd page
Merge remote-tracking branch 'upstream/master' into add_fluentd_doc

Conflicts:
	_site/archive.html
	_site/atom.xml
	_site/categories.html
	_site/index.html
	_site/lessons/2011/12/29/jekyll-introduction/index.html
	_site/new-page.html
	_site/pages.html
	_site/rss.xml
	_site/sitemap.txt
	_site/tags.html
	index.md
del logstash doc
Merge remote-tracking branch 'upstream/master' into add_fluentd_doc
add fluentd doc
Merge pull request #17 from lovemeng/add_fluentd_doc

Add fluentd doc