Description of problem:
Validation marks a human task by alert "User Task has no task form defined" when Task Name contains space, but the task form exists.

Version-Release number of selected component (if applicable):
BRMS 5.3.1 ER2, designer 2.3.1-DEV

How reproducible:
Every time

Steps to Reproduce:
1. Create simple process (Start->Human task->End)
2. Set property "Task Name" of Human task to "task name"
3. Click on icon "Generate task form"
4. Check if task form (task name-taskform.flt) exists in package
5. Validate process
  
Actual results:
The validator marks a human task by alert "User Task has no task form defined".

Expected results:
In case that space is valid character for Task Name: 
 - alert "There are no validation error".
In case that space is invalid character for Task Name: 
 - do not generate task form for invalid Task Name
 - validator marks a human task by alert "Task Name is not valid"

Additional info:
I do not find any integrity constraints for Task Name in documentation.