Changed the "posts" query to search for a tag

Current implementation only grabs direct children of the 
`posts` directory which breaks when you add sub-folders.

Updated implementation to avoid this problem and so behaviour
matches comment directly above...
Merge pull request #3 from vitch/patch-1

Changed the "posts" collection query to search for a tag and allow for subdirectories
Update docpad.coffee

Syntax error crept in: extra close brace.
Merge pull request #5 from mishaba/master

Syntax error in docpad.coffee
Duplicite in @getBlock('meta').toHTML()

<!-- Output DocPad produced meta elements -->
<%- @getBlock('meta').toHTML() %>
Merge pull request #6 from ondrek/patch-1

Duplicite in @getBlock('meta').toHTML()