- 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
Update collision detector to handle minimum-distance and repeat-distance seperately.
Update placement_finder to use repeat-distance.
Update group symbolizer to handle minimum-distance and repeat-distance.
Create a group_symbolizer_helper for group placments, and extract some code from
text_symbolizer_helper into a base class to share with group_symbolizer_helper.
Also, move tolerance_iterator into its own header file. Use helper in
process_group_symbolizer to find placement positions.
This includes XML parsing of group symbolizer and related objects and
process_group_symbolizer method in the AGG renderer. This also includes
code to collect group symbolizer indexed columns, create sub features,
and match them to group rules.
