Implemented capture screenshot on test failure

- feature is enabled by setting up property relativeScreenshotDirectory which point to directory where to store screenshots
- tests verify if screenshot is correctly created
Fix for multiplatform support - bcs. of WM is platform specific.
Fix compile time dependency bcs of platform WS specific.
Capture screenshot fixes:
- tycho support
- screenshots captured at the moment of failure, also in after and before
- fix default screenshots path
Update CaptureScreenshot.java
 Add support for expansion to UIFormSection fixes: #490
Fixed calling before classes
Fixed name of getItem method parameter

-it get item on the given index not row
DefaultCombo renamed to LabeledCombo and true DefaultCombo created (fixes #485)
Javadoc - modified, removed, added as it should be for jface plugin (fixes #465)
Fixed NPE when property was not defined
Fixed file separator for windows
fixed windows path parsing regex
Moved isVisible & isEnabled from lookup to handler. Fixes  #504
Updated matchers (renaming, documentation, refactoring) #482
typeText() method added to Text (fixes #169)
Fixed covering of original test failure cause by screenshot exceptions
Removed protected constructor.
Renamed classes in uiforms to use Eclipse names
Added condition which if fulfilled when table contains specified item