inital pass at re-working builder modals to support arbitrary screen resolutions
Merge pull request #53 from LibraryOfCongress/feature/monster-modal

inital pass at re-working builder modals
complete removal of canvas
eliminate use of handler500 with context
minor alignment of notice display (when there are none)
Display 'delete' modal when button is clicked next to a Property in the editor. Delete PropertyView from DOM.
Delete Property on the server after clicking delete button in the editor.
React to 'deletePropertSuccess' and 'deletePropertyError' events with descriptive error messages.