Add 'static' data source to Nanoc core.

The original author of this data source appears to be @ddfreyne. Data source code from here:

    http://pastie.textmate.org/914015

Update `create_site` command to include a stub configuration, routing rule and compilation rule for the static data source.
fixed 'passthrough' rule routing
Merge pull request #153 from gpakosz/fix-passthrough-routing

fixed 'passthrough' rule routing
fixed 'passthrough' rule routing
added test case for passthrough routing fix
added checker dsl
merged changes from 3.4.x branch
refactored error handler
refactored show-data command (still not ideal)
refactored show-data command more
refactored check command
refactored atom_feed method in blogging helper
refactored check command more
refactored atom feed builder
refactored check command
cleaned up passthrough-without-extension test case
made passthrough rules be inserted in the proper order (fixes #156)
Add support for Atom icon.
Add support for Atom logo.
Merge pull request #160 from RubenVerborgh/atom-icon-logo

Support Atom icon and logo