SWTBot dependencies removed from LabeledTextTest
SWTBot dependencies removed from DefaultTableTest
Bot class and it's references removed, missing API implemented
SWTBot dependencies removed from ComboTest
SWTBot dependencies removed from CTabFolderTest
SWTBot dependencies removed from ExpandBarTest
SWTBot dependencies removed from ProgressBarTest
REDDEER-256: Implement activate method into Shell class
Adds calling showView() method when opening view
DefaultTreeItem constructors refactored

Refactoring done to avoid code duplication and to clean
a code a bit. Also one additional constructor added:

DefaultTreeItem(Tree tree, int cellIndex, String... treeItemPath)
Tests added for DefaultTreeItem(Tree, cellIndex, String...) constructor - also tests' internal createTreeItems() methods extended to support more tree columns
SWTBot references removed from all RedDeer manifests
Log4j references removed from RedDeer (fixes #176)