Same name for global variables and work item input/output variables

Using the designer WAR it is not possible to have the same name for global variables and input/output variables for work items. When importing Processes that do so, the input mapping gets lost in the process.

To reproduce:

• create a process with the eclipse BPMN2 Process Editor
• define a global variable 'myVariable'
• add a work item and
  • map the global variable 'myVariable' to the input parameter 'myVariable'
  • map the output parameter 'myVariable' to the global variable 'myVariable'
• save the process
• open the web designer, create a new process and import the process
• export the process

The exported process now lacks an input mapping for the work item.