improve handling of format properties - refs #2516

 - changes evaluated_format_properties_ptr to unique_ptr
 - refactors group symbolizer helper to keep scope by
   having each "thunk" own its helper
 - glyph_info can now be noncopyable
 - format node children now need an owner for their
   evaluated_format_ptr so the enclosing parent layout
   now allocates and holds pointers in a deque
 - plus other noncopyable/move constructor fixes