Replace Content#pieces with Content#contents as the generic way to retrieve all of an object's content

Conten#pieces now returns only non-Page contents.
Use new Content#pieces method to return content in consistent order
Reject duplicate change set members
Support absolute paths
Allow for ENV setting to switch DB adapter
Stop saving of instance overwriting visibility in the DB
Ignore order in target list test
New Output implementation.

Outputs are now 'instances' of formats using configuration based on the
schema entry. All Page#render calls now go through the appropriate
output rather than this only being used during publish.
Replace Spontaneous.template_paths with Site.paths(:templates)

Still a lot of Spontaneous.*paths cruft to get rid of though.
Layouts can now be defined with a block
Render contexts are now dynamically generated according to the output.

You can now add helpers to a specific format/output with Site.helper
:format do … end.
Merge pull request #2 from magnetised/master

Fix for actions called on the homepage
Test for elements ignoring order
Regenerated gemspec
Preliminary support for non-content alias targets
Pages were unable to find their associated entry
Add missing functional test for adding pages to boxes
Add ability to search within alias targets
Adding first page now updates the location bar properly
Schema errors in preview mode no longer generate a 500