Package cleanup

- Remove unused ``*._develop.js`` bundles.
- Remove unused bundles ``toolbar`` and ``tiles``.
- Remove unused bower dependencies ``domready``, ``respond`` and ``html5shiv``.
- Move all NixOS plattform specific ``*.nix`` config files to a ``.nix`` subdirectory.
- Bower updates, except pickadate and backbone.paginator.

Fixes #425