Fix for act-1447, thanks Saeid
Fix for ACT-1449
IN PROGRESS - issue ACT-1445: Improve documentation for creating
Designer Extensions 
https://jira.codehaus.org/browse/ACT-1445

Added popup error message if the extension is not open. Processing JARs
that are not open to Eclipse will otherwise lead to errors.
Added Activiti BPMN converter and model
Upgraded to 5.11.0
Fixed custom property missing property fields
removed export bundle
Added support for Expressions for custom task properties
Updates for 5.11 release
Updates for 5.11 release
fixed process targetNamespace issue
Prepare for 5.11.1 release
Fixed custom extension class attribute bug
Fixed problem with radio choice custom property field
Updated examples pom
Fixed sub process multi instance and execution listener issue
Fix for boundary event in sub process
Getting ready for 5.11.2 release
- Rewrote diagram editor input handling in ActivitiDiagramEditor by
removing coupling to data- and diagram file.

- Introduced subclassed editor input ActivitiDiagramEditorInput that
references both data- and diagram file

- Made sure the newly subclassed version of the diagram editor input is
used when generating diagrams (either automatically via Eclipse IDE or
by wizard).

- Rewrote Matching Strategy so it correctly matches open editors, e.g.
by clicking the appropriate arrow in the preferences of a call activity. 

- Reactivated arrow in PropertyCallActivitiSection as a basic start.
* Modified correction to remove internal Graphiti API reference when
  creating a transactional domain.
  
* Consolidated constants into a class ActivitiConstants.java in the 
  utils project and let various other files now point to it rather than
  directly specifying things like extensions or texts.
  
* Modified Properties for asynchronous support. They used the wrong 
  event type FocusEvent of input fields. Rewrote them to use check 
  boxes for their boolean representation and used a SelectionListener
  instead so modifications only occur, when a selection/deselection
  occurrs.
  
* Implemented Call Activity Property selection. This will allow to open
  the appropriate process model when it's ID is found in one of the open
  projects in the Eclipse project explorer. In case multiple processes
  are found, the user is asked to select the one to open. 
  
* Created new package dialog in the utils package to host a modified
  version of the ResourceSelectionDialog, cause this one does not 
  support setting an initial pattern. This refers to bug 36029 in 
  Eclipse, where the appropriate method was available in Eclipse 3.3
  but is no longer existing in Eclipse 4.2.