Fully remove previous ID when performing `file.clone()`

This fixes https://github.com/docpad/docpad-plugin-multiplelayouts/issues/9 - I believe all 4 deletions are necessary due to the way things get munged together.
bah, semicolons!

I'm still thinking in JavaScript...
Fixing error message when docpad can't find the layout

I was getting the error
    ReferenceError: layoutSelector is not defined
      at ...\node_modules\docpad\out\lib\models\document.js:398:74
      ...

Instead of the more helpful `Error: Could not find the layout service-landing-page on /user-modeling.html` because `layoutSelector` wasn't defined in the `renderLayouts` function.

This fixes that.
Merge pull request #897 from nfriedly/patch-2

Fixing error message when docpad can't find the layout
Merge pull request #893 from nfriedly/patch-1

Fully remove previous ID when performing `file.clone()`
Updated deps and regen'd readme
Updated base files
Updated base files