First commit. HighlightableTextBlock control.
Add User Control for typing textblock and textbox.
Further changes.

If highlighting isn't initialized throw Exception.
Added styles during start countdown for text and typing box.
Dependency property for highlighting in the user control.
INotifyPropertyChanged for user control for future.
Add text processing for Symbol highlighting.
ProcessTyping refactoring.
Add ResourceDictionary for styles inside UserControl.
Text processing almost done.
Finish text processing.

Made finishing of typing text work and all related actions made.
Added TypingFinished event.