structure for unordered_multimap/unordered_multiset that uses an extra
pointer per node but makes most operations more efficient when equivalent
nodes are present.
Now uses macros instead of template metaprogramming to implement the
differences between containers with equivalent and unique keys.
Removed the erase_iterator stuff which complicated matters more than it helped.
Now just using pointers with some helper functions.
[SVN r2950]
Several changes:
- Makes insert meet its exception specification (but needs some refactoring).
- Some Borland work arounds, but not all there yet, maybe never will be.
- Some extra doxygen comments, but not nearly enough.
- Possibly other things that I'm too lazy to look up.
[SVN r2642]
