Using location.href instead of location.replace for js redirects.

That keeps browser history.
Fixes error when assigning file in essence_file.

Do not convert @options to json in essence_file assign action anymore.
[Release] 2.7.0
Adds a new option separator to render_elements helper.
Fixes a bug in `Modules#module_definition_for` if module has leading slash in controller name.
Fixes the width of buttons in the alchemy frontend menubar.
Adds html_options to `render_subnavigation` helper.
Refactors the Alchemy.Tinymce initialization. Closes #410

All editors now will be initialized as by id, instead of by class. This fixes reinit issues.
Fixes layout pages lockes status icon. Closes #409
Do not redirect to edit page template, if page redirects to external. Closes #408
Fixes true icon in ressources tables.
Adds a layout select box for new language form and translates the page layout in languages table.
Removes console.log call
Adds a callback option to PreviewWindow.refresh
Scroll to element in preview after saving element.
Lower the minimum width of preview and elements window.
Rearranged the image crop window, so it fits on small screens.
Focus the preview window after changing its size.
Fixes EssenceFile editor.

1. Fix bug where the overlay observer was called twice after assigning file.
2. Fixes layout issues.