Remove endless "!" inside admin templates

In earlier template parser versions, used in In-Portal we had problems
distinguishing simple text and labels, that should be translated. At that
times we invented ability to escape text with "Unable to render embedded object: File (" in form "!label_here) not found." so
it will be translated.

For quite some time this is no longer a problem and that ! in admin template
actually do nothing and are stripped at the end. Example code:
*<inp2:m_RenderElement name="inp_edit_options" prefix="formflds"
field="ElementType" title="Unable to render embedded object: File (la_prompt_InputType) not found."/>*

As you can notice title parameter value displays the problem I've described.
We will remove all such occurrences of "!" in one release and will remove
code, that strips ! in next version, so all users will be forced to to
change their code as well.