Update viewer to disable automatic escaping

Automatic expression escaping was introduced in version 1.5.1 of Aria Templates.
The samples viewer code needs to be updated accordingly.
Remove Aria Templates code

The code of the Aria Templates framework is not needed any longer.
0.2.1
Update viewer to disable automatic escaping for data model

Automatic expression escaping was introduced in version 1.5.1 of Aria Templates.
The samples viewer code needs to be updated accordingly.
0.2.2