Add UIItem hightlighting.
Add HighlightTimeout to configuration
Remove unused directive.
Made all methods virtual.
Add DrawHighlight to IUIItem.
Small improvement.
Moved highlighting to different thread
Add UIItem hightlighting.

Conflicts:
	src/TestStack.White/WindowsAPI/NativeWindow.cs
Add HighlightTimeout to configuration

Conflicts:
	src/TestStack.White/WindowsAPI/NativeWindow.cs
Remove unused directive.
Made all methods virtual.
Add DrawHighlight to IUIItem.
Small improvement.
Moved highlighting to different thread
Merge branch 'Issue144' of https://github.com/ilya-murzinov/White into Issue144

Conflicts:
	src/TestStack.White/WindowsAPI/NativeWindow.cs
fix & removed starting highlighting in another thread
Merge pull request #188 from ilya-murzinov/Issue144

Issue144: Add DrawHighlight method to UIItem