Add LEACString to layout areas as C Strings if the reference used for the layout
is a char pointer.

Also, disable the eliding behaviour of LEVCString, because:
- Graphviz will stretch the cells of shorter strings when rendering an array of
  strings.
- A single char array might logically contain multiple strings (e.g. due to
  strtok).

We may be able to detect the latter case by checking for references after NULL
characters, but for now don't worry about it because of the layout problem.