Implicit constructors on swt layer implemented
Workbench related implicit conditions implemented
Control associated with WorkbenchPartReference object is now used as
parent control for discovering widgets.
TreeItemFoundAfterExpanding is now used in DefaultTreeItem - should be
more stable when tree item is dynamically generated
ShellToolBar and ShellToolItem implemented + tests covering this new
objects
Fix for selecting default tree item
Methods from WorkbenchLookup were accidentally removed -> it is fixed now