Ext 5 support

[bmoeskau]

Get calendar working under Ext 5. Way more of a pain than it should be.

• [x] Get all calendar view layouts rendering correctly
• [x] Get in-memory examples rendering static test data correctly
• [x] Fix nav calendar display issues
• [x] Fix calendar color widget
• [ ] Fix edit window duplicate instance bug
• [ ] Fix event edit form
• [ ] Fix calendar panel CRUD / drag-drop persistence
• [ ] Fix remote examples not loading at all
• [ ] Fix runtime errors in recurrence fieldset
• [ ] Drag-to-create not setting start date correctly when start < end

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