Add Haiku stubs for org.eclipse.swt.program.*
Add stubbed org.eclipse.swt.awt.* for Haiku
Add stubbed org.eclipse.swt.dnd.* classes

Also add stubbed Tree* and Table* widget classes that are now needed.
Add stubbed org.eclipse.swt.printing.* Haiku classes
Add custom widgets to Haiku build

Add required dnd, graphics, and widget class stubs.