Fixed bug where Url specified in front matter as pretty url wouldnt render

Signed-off-by: Noah Campbell <noahcampbell@gmail.com>
Cleanup formatting - go fmt ./...

Remember to run go fmt ./... before committing.  Looks sternly in mirror
Revert "Return errors when rendering"

This reverts commit e66ba5d2a7dd1a043a24bf86a271a5440b7b1385.

Fixed #69
Ensure Section is set before returning Page object.
Externalize the writing of content to a target

Introducing the target module in hugo.  This provides the simple
interface for writing content given a label (filename) and a io.Reader
containing the content to be written.

If site.Target is not set, it defaults back to the original behavior of
writing to file system.

In hugolib/site_url_test.go I have an InMemoryTarget for testing
purposes and use it to see if the final output of a render matches.
Removing site.Directories.

Please revert if this is used somewhere.
Return an error with WritePublic