Work Progress - Dec 1 - Dec 7

Demo: here

• Robust handling of mistyped coordinates in SB
• Bug fix on JPnlLineProperty - no need to actually click and make selection before setting the corresponding object property
• Modify Bill's RW code to make it compatible with the latest core.
  
• Global variables are now available for drag-and-drop. Use them with care as it is still not perfect. (e.g. In [A = B + C], One can't insert a variable/an attribute to location B or C.)