- Refactored configuration code
- Created ConfigMenu class in sencha-core

  Fixed issue with end_date < start_date that leads to an error
  from the REST interface originally created by the database
  check-constraint. Now start_date <= end_date is enforced

  - Added CostCenter field
  - Added CostCenter model and store

  - Added read-only functionality and warnings

  (before, the last line was sometimes skipped)

  - Improved error message
  - Added remaining columns to GanttTreeStore (material)

  Now produces Beta warning when modifying the tree-model

  Saving the schedule now disables the Save button

- Fixed the display of resources behind a sprite

  - Added drag-and-drop configuration to all sprites,
    in order to allow them to act as source and target
    for dependencies
  - Fixed issue with negative width in percent-bars

  - Moved MS-Project Warning portlet to the bottom of the project page
  - Added "ReadOnly" configuration option to GanttEditor
  - Fixed GanttTreePanelController log messages
  - Fixed issue with "chain" icon not appearing in GanttEditor
  - Fixed issue with different "icons" per task after loading
  - Fixed issue with icon not changing after setting a task to milestone_p

  - Moved functionality to PO.Utilities.reportError()
  - Eliminated duplicate code from GanttButtonController

  function in the GanttBarPanel, where it also
  handles the restore of the zoom configuration

  - Now all scrolling is handled in the GanttZoomController
  - Focussing on a project includes a zoom on the center of
    the visible area
  - Both scroll and axis start- and end-dates are now persistent
    using preferences

  This is now all handled in the GanttZoomController.
- Fixed bug with loading preferences and moved preference
  functionality into the SenchaPreferenceStore

  from GanttZoomPanel to GanttBarPanel, where both
  the needsRedraw variable and the redraw() function
  are located.

  Now redrawing only if the needsRedraw variable is set to true

- ToDo: Factor error reporting out into a sencha-core functionality

  Now showing an error message instead of a blank screen if
  executed in a tab in a non-Gantt project

  indicating the type of object (task, project, ticket, ...)

  after setting milestone property in task
  property panel

  Fixed various issues